/*
* Copyright 2013 <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.ocpsoft.rewrite.servlet.config.response;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.GZIPOutputStream;
import org.ocpsoft.rewrite.exception.RewriteException;
import org.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;
/**
* A {@link ResponseStreamWrapper} that compresses the response output to GZip format and sets the proper response
* headers.
*
* @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*/
public class GZipResponseStreamWrapper implements ResponseStreamWrapper
{
public final static String STREAM_KEY = GZipResponseStreamWrapper.class.getName() + "_STREAM";
@Override
public OutputStream wrap(final HttpServletRewrite rewrite, OutputStream outputStream)
{
rewrite.getResponse().setHeader("Content-Encoding", "gzip");
try {
GZIPOutputStream stream = new GZIPOutputStream(outputStream);
rewrite.getRequest().setAttribute(STREAM_KEY, stream);
return stream;
}
catch (IOException e) {
throw new RewriteException("Could not wrap OutputStream", e);
}
}
@Override
public void finish(HttpServletRewrite rewrite)
{
try {
GZIPOutputStream stream = (GZIPOutputStream) rewrite.getRequest().getAttribute(STREAM_KEY);
if (stream != null)
{
stream.flush();
stream.finish();
}
}
catch (IOException e) {
throw new RewriteException("Could not finish GZip Encoding", e);
}
}
}