Merge pull request #306 from stephenc/offline-support

Add offline support to the API to make parsing events easier

src/main/java/org/kohsuke/github/GitHub.java

@@ -216,6 +216,24 @@ public class GitHub {
         return new GitHubBuilder().withEndpoint(apiUrl).build();
     }
 
+    /**
+     * An offline-only {@link GitHub} useful for parsing event notification from an unknown source.
+     *
+     * All operations that require a connection will fail.
+     *
+     * @return An offline-only {@link GitHub}.
+     */
+    public static GitHub offline() {
+        try {
+            return new GitHubBuilder()
+                    .withEndpoint("https://api.github.invalid")
+                    .withConnector(HttpConnector.OFFLINE)
+                    .build();
+        } catch (IOException e) {
+            throw new IllegalStateException("The offline implementation constructor should not connect", e);
+        }
+    }
+
     /**
      * Is this an anonymous connection
      * @return {@code true} if operations that require authentication will fail.
@@ -224,6 +242,14 @@ public class GitHub {
         return login==null && encodedAuthorization==null;
     }
 
+    /**
+     * Is this an always offline "connection".
+     * @return {@code true} if this is an always offline "connection".
+     */
+    public boolean isOffline() {
+        return connector == HttpConnector.OFFLINE;
+    }
+
     public HttpConnector getConnector() {
         return connector;
     }