diff --git a/modules/swagger-codegen/src/main/resources/Java/StringUtil.mustache b/modules/swagger-codegen/src/main/resources/Java/StringUtil.mustache
index c9583f1bc6..073966b0c2 100644
--- a/modules/swagger-codegen/src/main/resources/Java/StringUtil.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/StringUtil.mustache
@@ -39,13 +39,4 @@ public class StringUtil {
     }
     return out.toString();
   }
-
-  /**
-   * Convert the given object to string with each line indented by 4 spaces
-   * (except the first line).
-   */
-  public static String toIndentedString(Object o) {
-    if (o == null) return "null";
-    return o.toString().replace("\n", "\n    ");
-  }
 }
diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/model.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/model.mustache
index b7b4ea2cf3..0794a94f6d 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/model.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/model.mustache
@@ -65,14 +65,25 @@ public class {{classname}} {{#parent}}extends {{{parent}}}{{/parent}} {{#seriali
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class {{classname}} {\n");
-    {{#parent}}sb.append("    ").append(StringUtil.toIndentedString(super.toString())).append("\n");{{/parent}}
-    {{#vars}}sb.append("    {{name}}: ").append(StringUtil.toIndentedString({{name}})).append("\n");
+    {{#parent}}sb.append("    ").append(toIndentedString(super.toString())).append("\n");{{/parent}}
+    {{#vars}}sb.append("    {{name}}: ").append(toIndentedString({{name}})).append("\n");
     {{/vars}}sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
 {{/model}}
 {{/models}}
diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/model.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/model.mustache
index b7b4ea2cf3..0794a94f6d 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/model.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit/model.mustache
@@ -65,14 +65,25 @@ public class {{classname}} {{#parent}}extends {{{parent}}}{{/parent}} {{#seriali
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class {{classname}} {\n");
-    {{#parent}}sb.append("    ").append(StringUtil.toIndentedString(super.toString())).append("\n");{{/parent}}
-    {{#vars}}sb.append("    {{name}}: ").append(StringUtil.toIndentedString({{name}})).append("\n");
+    {{#parent}}sb.append("    ").append(toIndentedString(super.toString())).append("\n");{{/parent}}
+    {{#vars}}sb.append("    {{name}}: ").append(toIndentedString({{name}})).append("\n");
     {{/vars}}sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
 {{/model}}
 {{/models}}
diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/model.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/model.mustache
index b7b4ea2cf3..0794a94f6d 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/model.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/model.mustache
@@ -65,14 +65,25 @@ public class {{classname}} {{#parent}}extends {{{parent}}}{{/parent}} {{#seriali
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class {{classname}} {\n");
-    {{#parent}}sb.append("    ").append(StringUtil.toIndentedString(super.toString())).append("\n");{{/parent}}
-    {{#vars}}sb.append("    {{name}}: ").append(StringUtil.toIndentedString({{name}})).append("\n");
+    {{#parent}}sb.append("    ").append(toIndentedString(super.toString())).append("\n");{{/parent}}
+    {{#vars}}sb.append("    {{name}}: ").append(toIndentedString({{name}})).append("\n");
     {{/vars}}sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
 {{/model}}
 {{/models}}
diff --git a/modules/swagger-codegen/src/main/resources/Java/pojo.mustache b/modules/swagger-codegen/src/main/resources/Java/pojo.mustache
index 2e9facfb14..8d92141fa7 100644
--- a/modules/swagger-codegen/src/main/resources/Java/pojo.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/pojo.mustache
@@ -45,12 +45,23 @@ public class {{classname}} {{#parent}}extends {{{parent}}}{{/parent}} {{#seriali
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class {{classname}} {\n");
-    {{#parent}}sb.append("    ").append(StringUtil.toIndentedString(super.toString())).append("\n");{{/parent}}
-    {{#vars}}sb.append("    {{name}}: ").append(StringUtil.toIndentedString({{name}})).append("\n");
+    {{#parent}}sb.append("    ").append(toIndentedString(super.toString())).append("\n");{{/parent}}
+    {{#vars}}sb.append("    {{name}}: ").append(toIndentedString({{name}})).append("\n");
     {{/vars}}sb.append("}");
     return sb.toString();
   }
-}
\ No newline at end of file
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
+}
diff --git a/samples/client/petstore/java/default/src/main/java/io/swagger/client/StringUtil.java b/samples/client/petstore/java/default/src/main/java/io/swagger/client/StringUtil.java
index 4ba4ee3a2f..cd6112efeb 100644
--- a/samples/client/petstore/java/default/src/main/java/io/swagger/client/StringUtil.java
+++ b/samples/client/petstore/java/default/src/main/java/io/swagger/client/StringUtil.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-21T14:12:11.520+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:32:50.163+08:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).
@@ -39,13 +39,4 @@ public class StringUtil {
     }
     return out.toString();
   }
-
-  /**
-   * Convert the given object to string with each line indented by 4 spaces
-   * (except the first line).
-   */
-  public static String toIndentedString(Object o) {
-    if (o == null) return "null";
-    return o.toString().replace("\n", "\n    ");
-  }
 }
diff --git a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Category.java b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Category.java
index abcb97e84e..03efe0d240 100644
--- a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Category.java
+++ b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Category.java
@@ -11,7 +11,7 @@ import com.fasterxml.jackson.annotation.*;
 
 
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-21T14:12:11.520+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:32:50.163+08:00")
 public class Category   {
   
   private Long id = null;
@@ -62,13 +62,25 @@ public class Category   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Category {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Order.java b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Order.java
index b488fab6c3..fc1cb16b32 100644
--- a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Order.java
+++ b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Order.java
@@ -12,7 +12,7 @@ import com.fasterxml.jackson.annotation.*;
 
 
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-21T14:12:11.520+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:32:50.163+08:00")
 public class Order   {
   
   private Long id = null;
@@ -140,17 +140,29 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Order {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    petId: ").append(StringUtil.toIndentedString(petId)).append("\n");
-    sb.append("    quantity: ").append(StringUtil.toIndentedString(quantity)).append("\n");
-    sb.append("    shipDate: ").append(StringUtil.toIndentedString(shipDate)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
-    sb.append("    complete: ").append(StringUtil.toIndentedString(complete)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    petId: ").append(toIndentedString(petId)).append("\n");
+    sb.append("    quantity: ").append(toIndentedString(quantity)).append("\n");
+    sb.append("    shipDate: ").append(toIndentedString(shipDate)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
+    sb.append("    complete: ").append(toIndentedString(complete)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Pet.java b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Pet.java
index 5a979dcb73..d5577325a7 100644
--- a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Pet.java
+++ b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Pet.java
@@ -2,8 +2,8 @@ package io.swagger.client.model;
 
 import io.swagger.client.StringUtil;
 import io.swagger.client.model.Category;
-import io.swagger.client.model.Tag;
 import java.util.*;
+import io.swagger.client.model.Tag;
 
 
 import java.util.Objects;
@@ -14,7 +14,7 @@ import com.fasterxml.jackson.annotation.*;
 
 
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-21T14:12:11.520+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:32:50.163+08:00")
 public class Pet   {
   
   private Long id = null;
@@ -142,17 +142,29 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Pet {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    category: ").append(StringUtil.toIndentedString(category)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
-    sb.append("    photoUrls: ").append(StringUtil.toIndentedString(photoUrls)).append("\n");
-    sb.append("    tags: ").append(StringUtil.toIndentedString(tags)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    category: ").append(toIndentedString(category)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
+    sb.append("    photoUrls: ").append(toIndentedString(photoUrls)).append("\n");
+    sb.append("    tags: ").append(toIndentedString(tags)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Tag.java b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Tag.java
index 41cfb3d80d..66f5ea8474 100644
--- a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Tag.java
+++ b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/Tag.java
@@ -11,7 +11,7 @@ import com.fasterxml.jackson.annotation.*;
 
 
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-21T14:12:11.520+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:32:50.163+08:00")
 public class Tag   {
   
   private Long id = null;
@@ -62,13 +62,25 @@ public class Tag   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Tag {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/User.java b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/User.java
index 61960c622f..5f2ad2cd4c 100644
--- a/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/User.java
+++ b/samples/client/petstore/java/default/src/main/java/io/swagger/client/model/User.java
@@ -11,7 +11,7 @@ import com.fasterxml.jackson.annotation.*;
 
 
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-21T14:12:11.520+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:32:50.163+08:00")
 public class User   {
   
   private Long id = null;
@@ -147,19 +147,31 @@ public class User   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class User {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    username: ").append(StringUtil.toIndentedString(username)).append("\n");
-    sb.append("    firstName: ").append(StringUtil.toIndentedString(firstName)).append("\n");
-    sb.append("    lastName: ").append(StringUtil.toIndentedString(lastName)).append("\n");
-    sb.append("    email: ").append(StringUtil.toIndentedString(email)).append("\n");
-    sb.append("    password: ").append(StringUtil.toIndentedString(password)).append("\n");
-    sb.append("    phone: ").append(StringUtil.toIndentedString(phone)).append("\n");
-    sb.append("    userStatus: ").append(StringUtil.toIndentedString(userStatus)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    username: ").append(toIndentedString(username)).append("\n");
+    sb.append("    firstName: ").append(toIndentedString(firstName)).append("\n");
+    sb.append("    lastName: ").append(toIndentedString(lastName)).append("\n");
+    sb.append("    email: ").append(toIndentedString(email)).append("\n");
+    sb.append("    password: ").append(toIndentedString(password)).append("\n");
+    sb.append("    phone: ").append(toIndentedString(phone)).append("\n");
+    sb.append("    userStatus: ").append(toIndentedString(userStatus)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/StringUtil.java b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/StringUtil.java
index c843634389..bd924d2f4b 100644
--- a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/StringUtil.java
+++ b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/StringUtil.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-10T16:26:30.730+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:53:36.016+08:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).
@@ -39,13 +39,4 @@ public class StringUtil {
     }
     return out.toString();
   }
-
-  /**
-   * Convert the given object to string with each line indented by 4 spaces
-   * (except the first line).
-   */
-  public static String toIndentedString(Object o) {
-    if (o == null) return "null";
-    return o.toString().replace("\n", "\n    ");
-  }
 }
diff --git a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/ApiResponse.java b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/ApiResponse.java
deleted file mode 100644
index ab98bf61e8..0000000000
--- a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/ApiResponse.java
+++ /dev/null
@@ -1,92 +0,0 @@
-package io.swagger.client.model;
-
-import io.swagger.client.StringUtil;
-
-
-
-import java.util.Objects;
-
-import io.swagger.annotations.*;
-import com.fasterxml.jackson.annotation.JsonProperty;
-
-
-
-@ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-09T22:59:22.180-05:00")
-public class ApiResponse   {
-  
-  private Integer code = null;
-  private String type = null;
-  private String message = null;
-
-  
-  /**
-   **/
-  @ApiModelProperty(value = "")
-  @JsonProperty("code")
-  public Integer getCode() {
-    return code;
-  }
-  public void setCode(Integer code) {
-    this.code = code;
-  }
-
-  
-  /**
-   **/
-  @ApiModelProperty(value = "")
-  @JsonProperty("type")
-  public String getType() {
-    return type;
-  }
-  public void setType(String type) {
-    this.type = type;
-  }
-
-  
-  /**
-   **/
-  @ApiModelProperty(value = "")
-  @JsonProperty("message")
-  public String getMessage() {
-    return message;
-  }
-  public void setMessage(String message) {
-    this.message = message;
-  }
-
-  
-
-  @Override
-  public boolean equals(Object o) {
-    if (this == o) {
-      return true;
-    }
-    if (o == null || getClass() != o.getClass()) {
-      return false;
-    }
-    ApiResponse apiResponse = (ApiResponse) o;
-    return Objects.equals(code, apiResponse.code) &&
-        Objects.equals(type, apiResponse.type) &&
-        Objects.equals(message, apiResponse.message);
-  }
-
-  @Override
-  public int hashCode() {
-    return Objects.hash(code, type, message);
-  }
-
-  @Override
-  public String toString()  {
-    StringBuilder sb = new StringBuilder();
-    sb.append("class ApiResponse {\n");
-    
-    sb.append("    code: ").append(StringUtil.toIndentedString(code)).append("\n");
-    sb.append("    type: ").append(StringUtil.toIndentedString(type)).append("\n");
-    sb.append("    message: ").append(StringUtil.toIndentedString(message)).append("\n");
-    sb.append("}");
-    return sb.toString();
-  }
-}
-
-
diff --git a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Category.java b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Category.java
index 463da28c63..c0d16bbe2c 100644
--- a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Category.java
+++ b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Category.java
@@ -9,8 +9,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-10T16:26:30.730+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:53:36.016+08:00")
 public class Category   {
   
   private Long id = null;
@@ -61,13 +62,25 @@ public class Category   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Category {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Order.java b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Order.java
index 9b49076775..d2a2d7a66e 100644
--- a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Order.java
+++ b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Order.java
@@ -10,8 +10,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-10T16:26:30.730+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:53:36.016+08:00")
 public class Order   {
   
   private Long id = null;
@@ -139,17 +140,29 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Order {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    petId: ").append(StringUtil.toIndentedString(petId)).append("\n");
-    sb.append("    quantity: ").append(StringUtil.toIndentedString(quantity)).append("\n");
-    sb.append("    shipDate: ").append(StringUtil.toIndentedString(shipDate)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
-    sb.append("    complete: ").append(StringUtil.toIndentedString(complete)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    petId: ").append(toIndentedString(petId)).append("\n");
+    sb.append("    quantity: ").append(toIndentedString(quantity)).append("\n");
+    sb.append("    shipDate: ").append(toIndentedString(shipDate)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
+    sb.append("    complete: ").append(toIndentedString(complete)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Pet.java b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Pet.java
index 471bbe34b0..b7095d0e74 100644
--- a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Pet.java
+++ b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Pet.java
@@ -2,8 +2,8 @@ package io.swagger.client.model;
 
 import io.swagger.client.StringUtil;
 import io.swagger.client.model.Category;
-import io.swagger.client.model.Tag;
 import java.util.*;
+import io.swagger.client.model.Tag;
 
 
 import java.util.Objects;
@@ -12,8 +12,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-10T16:26:30.730+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:53:36.016+08:00")
 public class Pet   {
   
   private Long id = null;
@@ -141,17 +142,29 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Pet {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    category: ").append(StringUtil.toIndentedString(category)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
-    sb.append("    photoUrls: ").append(StringUtil.toIndentedString(photoUrls)).append("\n");
-    sb.append("    tags: ").append(StringUtil.toIndentedString(tags)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    category: ").append(toIndentedString(category)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
+    sb.append("    photoUrls: ").append(toIndentedString(photoUrls)).append("\n");
+    sb.append("    tags: ").append(toIndentedString(tags)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Tag.java b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Tag.java
index 02b5b85be4..b9469ad2a5 100644
--- a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Tag.java
+++ b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/Tag.java
@@ -9,8 +9,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-10T16:26:30.730+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:53:36.016+08:00")
 public class Tag   {
   
   private Long id = null;
@@ -61,13 +62,25 @@ public class Tag   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Tag {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/User.java b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/User.java
index 4d072f67d4..1fdfef1eec 100644
--- a/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/User.java
+++ b/samples/client/petstore/java/feign/src/main/java/io/swagger/client/model/User.java
@@ -9,8 +9,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-10T16:26:30.730+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:53:36.016+08:00")
 public class User   {
   
   private Long id = null;
@@ -146,19 +147,31 @@ public class User   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class User {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    username: ").append(StringUtil.toIndentedString(username)).append("\n");
-    sb.append("    firstName: ").append(StringUtil.toIndentedString(firstName)).append("\n");
-    sb.append("    lastName: ").append(StringUtil.toIndentedString(lastName)).append("\n");
-    sb.append("    email: ").append(StringUtil.toIndentedString(email)).append("\n");
-    sb.append("    password: ").append(StringUtil.toIndentedString(password)).append("\n");
-    sb.append("    phone: ").append(StringUtil.toIndentedString(phone)).append("\n");
-    sb.append("    userStatus: ").append(StringUtil.toIndentedString(userStatus)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    username: ").append(toIndentedString(username)).append("\n");
+    sb.append("    firstName: ").append(toIndentedString(firstName)).append("\n");
+    sb.append("    lastName: ").append(toIndentedString(lastName)).append("\n");
+    sb.append("    email: ").append(toIndentedString(email)).append("\n");
+    sb.append("    password: ").append(toIndentedString(password)).append("\n");
+    sb.append("    phone: ").append(toIndentedString(phone)).append("\n");
+    sb.append("    userStatus: ").append(toIndentedString(userStatus)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/StringUtil.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/StringUtil.java
index e9cc1341e0..1fa35d9ee7 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/StringUtil.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/StringUtil.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-29T00:18:01.946+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:35:06.891+08:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).
@@ -39,13 +39,4 @@ public class StringUtil {
     }
     return out.toString();
   }
-
-  /**
-   * Convert the given object to string with each line indented by 4 spaces
-   * (except the first line).
-   */
-  public static String toIndentedString(Object o) {
-    if (o == null) return "null";
-    return o.toString().replace("\n", "\n    ");
-  }
 }
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Category.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Category.java
index abe1bb895d..c0b1b559f9 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Category.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Category.java
@@ -9,8 +9,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-29T00:18:01.946+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:35:06.891+08:00")
 public class Category   {
   
   private Long id = null;
@@ -61,13 +62,25 @@ public class Category   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Category {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Order.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Order.java
index 6c90b3eca4..002d51a290 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Order.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Order.java
@@ -10,8 +10,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-29T00:18:01.946+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:35:06.891+08:00")
 public class Order   {
   
   private Long id = null;
@@ -139,17 +140,29 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Order {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    petId: ").append(StringUtil.toIndentedString(petId)).append("\n");
-    sb.append("    quantity: ").append(StringUtil.toIndentedString(quantity)).append("\n");
-    sb.append("    shipDate: ").append(StringUtil.toIndentedString(shipDate)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
-    sb.append("    complete: ").append(StringUtil.toIndentedString(complete)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    petId: ").append(toIndentedString(petId)).append("\n");
+    sb.append("    quantity: ").append(toIndentedString(quantity)).append("\n");
+    sb.append("    shipDate: ").append(toIndentedString(shipDate)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
+    sb.append("    complete: ").append(toIndentedString(complete)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Pet.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Pet.java
index 28343f0fc4..33126c58b7 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Pet.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Pet.java
@@ -2,8 +2,8 @@ package io.swagger.client.model;
 
 import io.swagger.client.StringUtil;
 import io.swagger.client.model.Category;
-import io.swagger.client.model.Tag;
 import java.util.*;
+import io.swagger.client.model.Tag;
 
 
 import java.util.Objects;
@@ -12,8 +12,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-29T00:18:01.946+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:35:06.891+08:00")
 public class Pet   {
   
   private Long id = null;
@@ -141,17 +142,29 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Pet {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    category: ").append(StringUtil.toIndentedString(category)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
-    sb.append("    photoUrls: ").append(StringUtil.toIndentedString(photoUrls)).append("\n");
-    sb.append("    tags: ").append(StringUtil.toIndentedString(tags)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    category: ").append(toIndentedString(category)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
+    sb.append("    photoUrls: ").append(toIndentedString(photoUrls)).append("\n");
+    sb.append("    tags: ").append(toIndentedString(tags)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Tag.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Tag.java
index a7ee39070c..28d7f5779a 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Tag.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/Tag.java
@@ -9,8 +9,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-29T00:18:01.946+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:35:06.891+08:00")
 public class Tag   {
   
   private Long id = null;
@@ -61,13 +62,25 @@ public class Tag   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Tag {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/User.java b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/User.java
index 5bfea7707f..d68a953a95 100644
--- a/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/User.java
+++ b/samples/client/petstore/java/jersey2/src/main/java/io/swagger/client/model/User.java
@@ -9,8 +9,9 @@ import io.swagger.annotations.*;
 import com.fasterxml.jackson.annotation.*;
 
 
+
 @ApiModel(description = "")
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-29T00:18:01.946+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:35:06.891+08:00")
 public class User   {
   
   private Long id = null;
@@ -146,19 +147,31 @@ public class User   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class User {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    username: ").append(StringUtil.toIndentedString(username)).append("\n");
-    sb.append("    firstName: ").append(StringUtil.toIndentedString(firstName)).append("\n");
-    sb.append("    lastName: ").append(StringUtil.toIndentedString(lastName)).append("\n");
-    sb.append("    email: ").append(StringUtil.toIndentedString(email)).append("\n");
-    sb.append("    password: ").append(StringUtil.toIndentedString(password)).append("\n");
-    sb.append("    phone: ").append(StringUtil.toIndentedString(phone)).append("\n");
-    sb.append("    userStatus: ").append(StringUtil.toIndentedString(userStatus)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    username: ").append(toIndentedString(username)).append("\n");
+    sb.append("    firstName: ").append(toIndentedString(firstName)).append("\n");
+    sb.append("    lastName: ").append(toIndentedString(lastName)).append("\n");
+    sb.append("    email: ").append(toIndentedString(email)).append("\n");
+    sb.append("    password: ").append(toIndentedString(password)).append("\n");
+    sb.append("    phone: ").append(toIndentedString(phone)).append("\n");
+    sb.append("    userStatus: ").append(toIndentedString(userStatus)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
+
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
index 3a105a258e..e67d875db4 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-07T12:21:33.403+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:33:26.877+08:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).
@@ -39,13 +39,4 @@ public class StringUtil {
     }
     return out.toString();
   }
-
-  /**
-   * Convert the given object to string with each line indented by 4 spaces
-   * (except the first line).
-   */
-  public static String toIndentedString(Object o) {
-    if (o == null) return "null";
-    return o.toString().replace("\n", "\n    ");
-  }
 }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Category.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Category.java
index 4f15da15c6..25ca3dbe94 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Category.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Category.java
@@ -64,13 +64,24 @@ public class Category   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Category {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Order.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Order.java
index 18c51201ad..3e9c7bb076 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Order.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Order.java
@@ -149,17 +149,28 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Order {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    petId: ").append(StringUtil.toIndentedString(petId)).append("\n");
-    sb.append("    quantity: ").append(StringUtil.toIndentedString(quantity)).append("\n");
-    sb.append("    shipDate: ").append(StringUtil.toIndentedString(shipDate)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
-    sb.append("    complete: ").append(StringUtil.toIndentedString(complete)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    petId: ").append(toIndentedString(petId)).append("\n");
+    sb.append("    quantity: ").append(toIndentedString(quantity)).append("\n");
+    sb.append("    shipDate: ").append(toIndentedString(shipDate)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
+    sb.append("    complete: ").append(toIndentedString(complete)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Pet.java
index 7e771866b3..d67add42e2 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Pet.java
@@ -151,17 +151,28 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Pet {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    category: ").append(StringUtil.toIndentedString(category)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
-    sb.append("    photoUrls: ").append(StringUtil.toIndentedString(photoUrls)).append("\n");
-    sb.append("    tags: ").append(StringUtil.toIndentedString(tags)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    category: ").append(toIndentedString(category)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
+    sb.append("    photoUrls: ").append(toIndentedString(photoUrls)).append("\n");
+    sb.append("    tags: ").append(toIndentedString(tags)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Tag.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Tag.java
index 474904011f..b444bf8748 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Tag.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/Tag.java
@@ -64,13 +64,24 @@ public class Tag   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Tag {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/User.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/User.java
index 82f1a0822d..8fbc8cbd23 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/User.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/model/User.java
@@ -155,19 +155,30 @@ public class User   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class User {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    username: ").append(StringUtil.toIndentedString(username)).append("\n");
-    sb.append("    firstName: ").append(StringUtil.toIndentedString(firstName)).append("\n");
-    sb.append("    lastName: ").append(StringUtil.toIndentedString(lastName)).append("\n");
-    sb.append("    email: ").append(StringUtil.toIndentedString(email)).append("\n");
-    sb.append("    password: ").append(StringUtil.toIndentedString(password)).append("\n");
-    sb.append("    phone: ").append(StringUtil.toIndentedString(phone)).append("\n");
-    sb.append("    userStatus: ").append(StringUtil.toIndentedString(userStatus)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    username: ").append(toIndentedString(username)).append("\n");
+    sb.append("    firstName: ").append(toIndentedString(firstName)).append("\n");
+    sb.append("    lastName: ").append(toIndentedString(lastName)).append("\n");
+    sb.append("    email: ").append(toIndentedString(email)).append("\n");
+    sb.append("    password: ").append(toIndentedString(password)).append("\n");
+    sb.append("    phone: ").append(toIndentedString(phone)).append("\n");
+    sb.append("    userStatus: ").append(toIndentedString(userStatus)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/StringUtil.java b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/StringUtil.java
index fa3abdc9c7..3f54bb1c01 100644
--- a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/StringUtil.java
+++ b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/StringUtil.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-29T00:18:14.988+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:34:07.014+08:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).
@@ -39,13 +39,4 @@ public class StringUtil {
     }
     return out.toString();
   }
-
-  /**
-   * Convert the given object to string with each line indented by 4 spaces
-   * (except the first line).
-   */
-  public static String toIndentedString(Object o) {
-    if (o == null) return "null";
-    return o.toString().replace("\n", "\n    ");
-  }
 }
diff --git a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/ApiResponse.java b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/ApiResponse.java
deleted file mode 100644
index 777de9a34e..0000000000
--- a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/ApiResponse.java
+++ /dev/null
@@ -1,72 +0,0 @@
-package io.swagger.client.model;
-
-import io.swagger.client.StringUtil;
-
-import com.google.gson.annotations.SerializedName;
-
-
-
-import io.swagger.annotations.*;
-
-
-
-@ApiModel(description = "")
-public class ApiResponse   {
-  
-  @SerializedName("code")
-  private Integer code = null;
-  
-  @SerializedName("type")
-  private String type = null;
-  
-  @SerializedName("message")
-  private String message = null;
-  
-
-  
-  /**
-   **/
-  @ApiModelProperty(value = "")
-  public Integer getCode() {
-    return code;
-  }
-  public void setCode(Integer code) {
-    this.code = code;
-  }
-
-  
-  /**
-   **/
-  @ApiModelProperty(value = "")
-  public String getType() {
-    return type;
-  }
-  public void setType(String type) {
-    this.type = type;
-  }
-
-  
-  /**
-   **/
-  @ApiModelProperty(value = "")
-  public String getMessage() {
-    return message;
-  }
-  public void setMessage(String message) {
-    this.message = message;
-  }
-
-  
-
-  @Override
-  public String toString()  {
-    StringBuilder sb = new StringBuilder();
-    sb.append("class ApiResponse {\n");
-    
-    sb.append("    code: ").append(StringUtil.toIndentedString(code)).append("\n");
-    sb.append("    type: ").append(StringUtil.toIndentedString(type)).append("\n");
-    sb.append("    message: ").append(StringUtil.toIndentedString(message)).append("\n");
-    sb.append("}");
-    return sb.toString();
-  }
-}
diff --git a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Category.java b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Category.java
index 4f15da15c6..25ca3dbe94 100644
--- a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Category.java
+++ b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Category.java
@@ -64,13 +64,24 @@ public class Category   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Category {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Order.java b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Order.java
index 18c51201ad..3e9c7bb076 100644
--- a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Order.java
+++ b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Order.java
@@ -149,17 +149,28 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Order {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    petId: ").append(StringUtil.toIndentedString(petId)).append("\n");
-    sb.append("    quantity: ").append(StringUtil.toIndentedString(quantity)).append("\n");
-    sb.append("    shipDate: ").append(StringUtil.toIndentedString(shipDate)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
-    sb.append("    complete: ").append(StringUtil.toIndentedString(complete)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    petId: ").append(toIndentedString(petId)).append("\n");
+    sb.append("    quantity: ").append(toIndentedString(quantity)).append("\n");
+    sb.append("    shipDate: ").append(toIndentedString(shipDate)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
+    sb.append("    complete: ").append(toIndentedString(complete)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Pet.java b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Pet.java
index bc3b80370b..d67add42e2 100644
--- a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Pet.java
@@ -2,8 +2,8 @@ package io.swagger.client.model;
 
 import io.swagger.client.StringUtil;
 import io.swagger.client.model.Category;
-import io.swagger.client.model.Tag;
 import java.util.*;
+import io.swagger.client.model.Tag;
 
 import com.google.gson.annotations.SerializedName;
 
@@ -151,17 +151,28 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Pet {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    category: ").append(StringUtil.toIndentedString(category)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
-    sb.append("    photoUrls: ").append(StringUtil.toIndentedString(photoUrls)).append("\n");
-    sb.append("    tags: ").append(StringUtil.toIndentedString(tags)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    category: ").append(toIndentedString(category)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
+    sb.append("    photoUrls: ").append(toIndentedString(photoUrls)).append("\n");
+    sb.append("    tags: ").append(toIndentedString(tags)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Tag.java b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Tag.java
index 474904011f..b444bf8748 100644
--- a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Tag.java
+++ b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/Tag.java
@@ -64,13 +64,24 @@ public class Tag   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Tag {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/User.java b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/User.java
index 82f1a0822d..8fbc8cbd23 100644
--- a/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/User.java
+++ b/samples/client/petstore/java/retrofit/src/main/java/io/swagger/client/model/User.java
@@ -155,19 +155,30 @@ public class User   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class User {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    username: ").append(StringUtil.toIndentedString(username)).append("\n");
-    sb.append("    firstName: ").append(StringUtil.toIndentedString(firstName)).append("\n");
-    sb.append("    lastName: ").append(StringUtil.toIndentedString(lastName)).append("\n");
-    sb.append("    email: ").append(StringUtil.toIndentedString(email)).append("\n");
-    sb.append("    password: ").append(StringUtil.toIndentedString(password)).append("\n");
-    sb.append("    phone: ").append(StringUtil.toIndentedString(phone)).append("\n");
-    sb.append("    userStatus: ").append(StringUtil.toIndentedString(userStatus)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    username: ").append(toIndentedString(username)).append("\n");
+    sb.append("    firstName: ").append(toIndentedString(firstName)).append("\n");
+    sb.append("    lastName: ").append(toIndentedString(lastName)).append("\n");
+    sb.append("    email: ").append(toIndentedString(email)).append("\n");
+    sb.append("    password: ").append(toIndentedString(password)).append("\n");
+    sb.append("    phone: ").append(toIndentedString(phone)).append("\n");
+    sb.append("    userStatus: ").append(toIndentedString(userStatus)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit2/README.md b/samples/client/petstore/java/retrofit2/README.md
new file mode 100644
index 0000000000..1a6255eb56
--- /dev/null
+++ b/samples/client/petstore/java/retrofit2/README.md
@@ -0,0 +1,43 @@
+# swagger-petstore-retrofit2
+
+## Requirements
+
+Building the API client library requires [Maven](https://maven.apache.org/) to be installed.
+
+## Installation & Usage
+
+To install the API client library to your local Maven repository, simply execute:
+
+```shell
+mvn install
+```
+
+To deploy it to a remote Maven repository instead, configure the settings of the repository and execute:
+
+```shell
+mvn deploy
+```
+
+Refer to the [official documentation](https://maven.apache.org/plugins/maven-deploy-plugin/usage.html) for more information.
+
+After the client libarary is installed/deployed, you can use it in your Maven project by adding the following to your *pom.xml*:
+
+```xml
+<dependency>
+    <groupId>io.swagger</groupId>
+    <artifactId>swagger-petstore-retrofit2</artifactId>
+    <version>1.0.0</version>
+    <scope>compile</scope>
+</dependency>
+
+```
+
+## Recommendation
+
+It's recommended to create an instance of `ApiClient` per thread in a multithreaded environment to avoid any potential issue.
+
+## Author
+
+apiteam@swagger.io
+
+
diff --git a/samples/client/petstore/java/retrofit2/src/main/AndroidManifest.xml b/samples/client/petstore/java/retrofit2/src/main/AndroidManifest.xml
new file mode 100644
index 0000000000..465dcb520c
--- /dev/null
+++ b/samples/client/petstore/java/retrofit2/src/main/AndroidManifest.xml
@@ -0,0 +1,3 @@
+<manifest package="io.swagger.client" xmlns:android="http://schemas.android.com/apk/res/android">
+    <application />
+</manifest>
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/StringUtil.java b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/StringUtil.java
index 47f9908c4d..9beb93a846 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/StringUtil.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/StringUtil.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-11-28T16:01:49.902+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2015-12-29T11:39:24.077+08:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).
@@ -39,13 +39,4 @@ public class StringUtil {
     }
     return out.toString();
   }
-
-  /**
-   * Convert the given object to string with each line indented by 4 spaces
-   * (except the first line).
-   */
-  public static String toIndentedString(Object o) {
-    if (o == null) return "null";
-    return o.toString().replace("\n", "\n    ");
-  }
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Category.java b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Category.java
index 4f15da15c6..25ca3dbe94 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Category.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Category.java
@@ -64,13 +64,24 @@ public class Category   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Category {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Order.java b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Order.java
index 18c51201ad..3e9c7bb076 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Order.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Order.java
@@ -149,17 +149,28 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Order {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    petId: ").append(StringUtil.toIndentedString(petId)).append("\n");
-    sb.append("    quantity: ").append(StringUtil.toIndentedString(quantity)).append("\n");
-    sb.append("    shipDate: ").append(StringUtil.toIndentedString(shipDate)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
-    sb.append("    complete: ").append(StringUtil.toIndentedString(complete)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    petId: ").append(toIndentedString(petId)).append("\n");
+    sb.append("    quantity: ").append(toIndentedString(quantity)).append("\n");
+    sb.append("    shipDate: ").append(toIndentedString(shipDate)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
+    sb.append("    complete: ").append(toIndentedString(complete)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Pet.java b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Pet.java
index bc3b80370b..d67add42e2 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Pet.java
@@ -2,8 +2,8 @@ package io.swagger.client.model;
 
 import io.swagger.client.StringUtil;
 import io.swagger.client.model.Category;
-import io.swagger.client.model.Tag;
 import java.util.*;
+import io.swagger.client.model.Tag;
 
 import com.google.gson.annotations.SerializedName;
 
@@ -151,17 +151,28 @@ public enum StatusEnum {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Pet {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    category: ").append(StringUtil.toIndentedString(category)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
-    sb.append("    photoUrls: ").append(StringUtil.toIndentedString(photoUrls)).append("\n");
-    sb.append("    tags: ").append(StringUtil.toIndentedString(tags)).append("\n");
-    sb.append("    status: ").append(StringUtil.toIndentedString(status)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    category: ").append(toIndentedString(category)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
+    sb.append("    photoUrls: ").append(toIndentedString(photoUrls)).append("\n");
+    sb.append("    tags: ").append(toIndentedString(tags)).append("\n");
+    sb.append("    status: ").append(toIndentedString(status)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Tag.java b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Tag.java
index 474904011f..b444bf8748 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Tag.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/Tag.java
@@ -64,13 +64,24 @@ public class Tag   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class Tag {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    name: ").append(StringUtil.toIndentedString(name)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    name: ").append(toIndentedString(name)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/User.java b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/User.java
index 82f1a0822d..8fbc8cbd23 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/User.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/io/swagger/client/model/User.java
@@ -155,19 +155,30 @@ public class User   {
   }
 
   @Override
-  public String toString()  {
+  public String toString() {
     StringBuilder sb = new StringBuilder();
     sb.append("class User {\n");
     
-    sb.append("    id: ").append(StringUtil.toIndentedString(id)).append("\n");
-    sb.append("    username: ").append(StringUtil.toIndentedString(username)).append("\n");
-    sb.append("    firstName: ").append(StringUtil.toIndentedString(firstName)).append("\n");
-    sb.append("    lastName: ").append(StringUtil.toIndentedString(lastName)).append("\n");
-    sb.append("    email: ").append(StringUtil.toIndentedString(email)).append("\n");
-    sb.append("    password: ").append(StringUtil.toIndentedString(password)).append("\n");
-    sb.append("    phone: ").append(StringUtil.toIndentedString(phone)).append("\n");
-    sb.append("    userStatus: ").append(StringUtil.toIndentedString(userStatus)).append("\n");
+    sb.append("    id: ").append(toIndentedString(id)).append("\n");
+    sb.append("    username: ").append(toIndentedString(username)).append("\n");
+    sb.append("    firstName: ").append(toIndentedString(firstName)).append("\n");
+    sb.append("    lastName: ").append(toIndentedString(lastName)).append("\n");
+    sb.append("    email: ").append(toIndentedString(email)).append("\n");
+    sb.append("    password: ").append(toIndentedString(password)).append("\n");
+    sb.append("    phone: ").append(toIndentedString(phone)).append("\n");
+    sb.append("    userStatus: ").append(toIndentedString(userStatus)).append("\n");
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Convert the given object to string with each line indented by 4 spaces
+   * (except the first line).
+   */
+  private String toIndentedString(Object o) {
+    if (o == null) {
+      return "null";
+    }
+    return o.toString().replace("\n", "\n    ");
+  }
 }