/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.client.protocol;
import java.io.IOException;
import java.io.InputStream;
import java.util.Locale;
import java.util.zip.GZIPInputStream;
import org.apache.http.Header;
import org.apache.http.HeaderElement;
import org.apache.http.HttpEntity;
import org.apache.http.HttpException;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.annotation.Immutable;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.DecompressingEntity;
import org.apache.http.client.entity.DeflateInputStream;
import org.apache.http.client.entity.InputStreamFactory;
import org.apache.http.config.Lookup;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.protocol.HttpContext;
/**
* {@link HttpResponseInterceptor} responsible for processing Content-Encoding
* responses.
* <p>
* Instances of this class are stateless and immutable, therefore threadsafe.
*
* @since 4.1
*
*/
@Immutable
public class ResponseContentEncoding implements HttpResponseInterceptor {
public static final String UNCOMPRESSED = "http.client.response.uncompressed";
private final static InputStreamFactory GZIP = new InputStreamFactory() {
@Override
public InputStream create(final InputStream instream) throws IOException {
return new GZIPInputStream(instream);
}
};
private final static InputStreamFactory DEFLATE = new InputStreamFactory() {
@Override
public InputStream create(final InputStream instream) throws IOException {
return new DeflateInputStream(instream);
}
};
private final Lookup<InputStreamFactory> decoderRegistry;
/**
* @since 4.4
*/
public ResponseContentEncoding(final Lookup<InputStreamFactory> decoderRegistry) {
this.decoderRegistry = decoderRegistry != null ? decoderRegistry :
RegistryBuilder.<InputStreamFactory>create()
.register("gzip", GZIP)
.register("x-gzip", GZIP)
.register("deflate", DEFLATE)
.build();
}
/**
* Handles {@code gzip} and {@code deflate} compressed entities by using the following
* decoders:
* <ul>
* <li>gzip - see {@link GZIPInputStream}</li>
* <li>deflate - see {@link DeflateInputStream}</li>
* </ul>
*/
public ResponseContentEncoding() {
this(null);
}
@Override
public void process(
final HttpResponse response,
final HttpContext context) throws HttpException, IOException {
final HttpEntity entity = response.getEntity();
final HttpClientContext clientContext = HttpClientContext.adapt(context);
final RequestConfig requestConfig = clientContext.getRequestConfig();
// entity can be null in case of 304 Not Modified, 204 No Content or similar
// check for zero length entity.
if (requestConfig.isDecompressionEnabled() && entity != null && entity.getContentLength() != 0) {
final Header ceheader = entity.getContentEncoding();
if (ceheader != null) {
final HeaderElement[] codecs = ceheader.getElements();
for (final HeaderElement codec : codecs) {
final String codecname = codec.getName().toLowerCase(Locale.ROOT);
final InputStreamFactory decoderFactory = decoderRegistry.lookup(codecname);
if (decoderFactory != null) {
response.setEntity(new DecompressingEntity(response.getEntity(), decoderFactory));
response.removeHeaders("Content-Length");
response.removeHeaders("Content-Encoding");
response.removeHeaders("Content-MD5");
} else {
if (!"identity".equals(codecname)) {
throw new HttpException("Unsupported Content-Coding: " + codec.getName());
}
}
}
}
}
}
}