Methods contentLength and transferEncoding added (#2490)

Methods contentLength and transferEncoding added to response headers

Signed-off-by: David Kral <david.k.kral@oracle.com>

webclient/webclient/src/main/java/io/helidon/webclient/NettyClientHandler.java

@@ -197,12 +197,13 @@ class NettyClientHandler extends SimpleChannelInboundHandler<HttpObject> {
     }
 
     private boolean noContentLength(WebClientResponseHeaders headers) {
-        return headers.first(Http.Header.CONTENT_LENGTH).isEmpty()
-                || headers.first(Http.Header.CONTENT_LENGTH).get().equals("0");
+        return headers.contentLength()
+                .map(value -> value == 0)
+                .orElse(true);
     }
 
     private boolean notChunked(WebClientResponseHeaders headers) {
-        return headers.first(Http.Header.TRANSFER_ENCODING).isEmpty();
+        return !headers.transferEncoding().contains("chunked");
     }
 
     @Override

webclient/webclient/src/main/java/io/helidon/webclient/WebClientResponseHeaders.java

@@ -79,4 +79,19 @@ public interface WebClientResponseHeaders extends Headers {
      */
     Optional<String> etag();
 
+    /**
+     * Content length of the response payload.
+     *
+     * @return content length
+     */
+    Optional<Long> contentLength();
+
+    /**
+     * Transfer encoding of the response.
+     *
+     * @return transfer encoding
+     */
+    List<String> transferEncoding();
+
+
 }

webclient/webclient/src/main/java/io/helidon/webclient/WebClientResponseHeadersImpl.java

@@ -95,6 +95,18 @@ class WebClientResponseHeadersImpl extends ReadOnlyParameters implements WebClie
         return first(Http.Header.ETAG).map(this::unquoteETag);
     }
 
+    @Override
+    public Optional<Long> contentLength() {
+        return first(Http.Header.CONTENT_LENGTH)
+                .map(Long::parseLong)
+                .or(Optional::empty);
+    }
+
+    @Override
+    public List<String> transferEncoding() {
+        return all(Http.Header.TRANSFER_ENCODING);
+    }
+
     private String unquoteETag(String etag) {
         if (etag == null || etag.isEmpty()) {
             return etag;