Minor clean: align calculateCharset on 1.9 and return a Charset

Author: Stephane Landelle

api/src/main/java/org/asynchttpclient/providers/ResponseBase.java

@@ -11,11 +11,11 @@
 import org.asynchttpclient.uri.Uri;
 import org.asynchttpclient.util.AsyncHttpProviderUtils;
 
+import java.nio.charset.Charset;
 import java.util.Collections;
 import java.util.List;
 
 public abstract class ResponseBase implements Response {
-    protected final static String DEFAULT_CHARSET = "ISO-8859-1";
 
     protected final List<HttpResponseBodyPart> bodyParts;
     protected final HttpResponseHeaders headers;
@@ -30,14 +30,14 @@ protected ResponseBase(HttpResponseStatus status, HttpResponseHeaders headers, L
 
     protected abstract List<Cookie> buildCookies();
 
-    protected String calculateCharset(String charset) {
+    protected Charset calculateCharset(String charset) {
 
         if (charset == null) {
             String contentType = getContentType();
             if (contentType != null)
                 charset = AsyncHttpProviderUtils.parseCharset(contentType); // parseCharset can return null
         }
-        return charset != null ? charset : DEFAULT_CHARSET;
+        return charset != null ? Charset.forName(charset) : AsyncHttpProviderUtils.DEFAULT_CHARSET;
     }
 
     @Override

providers/grizzly/src/main/java/org/asynchttpclient/providers/grizzly/GrizzlyResponse.java

@@ -69,7 +69,6 @@ public InputStream getResponseBodyAsStream() throws IOException {
      * {@inheritDoc}
      */
     public String getResponseBodyExcerpt(int maxLength, String charset) throws IOException {
-        charset = calculateCharset(charset);
         final Buffer responseBody = getResponseBody0();
         final int len = Math.min(responseBody.remaining(), maxLength);
         final int pos = responseBody.position();

providers/netty4/src/main/java/org/asynchttpclient/providers/netty4/response/NettyResponse.java

@@ -49,10 +49,9 @@ public String getResponseBodyExcerpt(int maxLength) throws IOException {
     }
 
     public String getResponseBodyExcerpt(int maxLength, String charset) throws IOException {
-        // should be fine; except that it may split multi-byte chars (last char may become '?')
-        charset = calculateCharset(charset);
         byte[] b = contentToBytes(bodyParts, maxLength);
-        return new String(b, charset);
+        // should be fine; except that it may split multi-byte chars (last char may become '?')
+        return new String(b, calculateCharset(charset));
     }
 
     protected List<Cookie> buildCookies() {