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 * 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/>.
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 */
package org.apache.http.impl.client;

import java.io.IOException;
import java.net.URI;

import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.client.protocol.RequestAcceptEncoding;
import org.apache.http.client.protocol.ResponseContentEncoding;
import org.apache.http.client.utils.URIUtils;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.params.HttpParams;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;

Decorator adding support for compressed responses. This class sets the Accept-Encoding header on requests to indicate support for the gzip and deflate compression schemes; it then checks the Content-Encoding header on the response to uncompress any compressed response bodies. The InputStream of the entity will contain the uncompressed content.
N.B. Any upstream clients of this class need to be aware that this effectively obscures visibility into the length of a server response body, since the Content-Length header will correspond to the compressed entity length received from the server, but the content length experienced by reading the response body may be different (hopefully higher!).
That said, this decorator is compatible with the CachingHttpClient in that the two decorators can be added in either order and still have cacheable responses be cached.
Since:
4.2
Deprecated:
(4.3) use HttpClientBuilder/**
 * <p>Decorator adding support for compressed responses. This class sets
 * the {@code Accept-Encoding} header on requests to indicate
 * support for the {@code gzip} and {@code deflate}
 * compression schemes; it then checks the {@code Content-Encoding}
 * header on the response to uncompress any compressed response bodies.
 * The {@link java.io.InputStream} of the entity will contain the uncompressed
 * content.</p>
 *
 * <p><b>N.B.</b> Any upstream clients of this class need to be aware that
 * this effectively obscures visibility into the length of a server
 * response body, since the {@code Content-Length} header will
 * correspond to the compressed entity length received from the server,
 * but the content length experienced by reading the response body may
 * be different (hopefully higher!).</p>
 *
 * <p>That said, this decorator is compatible with the
 * {@code CachingHttpClient} in that the two decorators can be added
 * in either order and still have cacheable responses be cached.</p>
 *
 * @since 4.2
 *
 * @deprecated (4.3) use {@link HttpClientBuilder}
 */
@Deprecated
public class DecompressingHttpClient implements HttpClient {

    private final HttpClient backend;
    private final HttpRequestInterceptor acceptEncodingInterceptor;
    private final HttpResponseInterceptor contentEncodingInterceptor;

    
Constructs a decorator to ask for and handle compressed
entities on the fly.
/**
     * Constructs a decorator to ask for and handle compressed
     * entities on the fly.
     */
    public DecompressingHttpClient() {
        this(new DefaultHttpClient());
    }

    
Constructs a decorator to ask for and handle compressed
entities on the fly.
Params:
backend – the HttpClient to use for actually issuing requests/**
     * Constructs a decorator to ask for and handle compressed
     * entities on the fly.
     * @param backend the {@link HttpClient} to use for actually
     *   issuing requests
     */
    public DecompressingHttpClient(final HttpClient backend) {
        this(backend, new RequestAcceptEncoding(), new ResponseContentEncoding());
    }

    DecompressingHttpClient(final HttpClient backend,
            final HttpRequestInterceptor requestInterceptor,
            final HttpResponseInterceptor responseInterceptor) {
        this.backend = backend;
        this.acceptEncodingInterceptor = requestInterceptor;
        this.contentEncodingInterceptor = responseInterceptor;
    }

    @Override
    public HttpParams getParams() {
        return backend.getParams();
    }

    @Override
    public ClientConnectionManager getConnectionManager() {
        return backend.getConnectionManager();
    }

    @Override
    public HttpResponse execute(final HttpUriRequest request) throws IOException,
            ClientProtocolException {
        return execute(getHttpHost(request), request, (HttpContext)null);
    }

    
Gets the HttpClient to issue request.
Returns:
the HttpClient to issue request/**
     * Gets the HttpClient to issue request.
     *
     * @return the HttpClient to issue request
     */
    public HttpClient getHttpClient() {
        return this.backend;
    }

    HttpHost getHttpHost(final HttpUriRequest request) {
        final URI uri = request.getURI();
        return URIUtils.extractHost(uri);
    }

    @Override
    public HttpResponse execute(final HttpUriRequest request, final HttpContext context)
            throws IOException, ClientProtocolException {
        return execute(getHttpHost(request), request, context);
    }

    @Override
    public HttpResponse execute(final HttpHost target, final HttpRequest request)
            throws IOException, ClientProtocolException {
        return execute(target, request, (HttpContext)null);
    }

    @Override
    public HttpResponse execute(final HttpHost target, final HttpRequest request,
            final HttpContext context) throws IOException, ClientProtocolException {
        try {
            final HttpContext localContext = context != null ? context : new BasicHttpContext();
            final HttpRequest wrapped;
            if (request instanceof HttpEntityEnclosingRequest) {
                wrapped = new EntityEnclosingRequestWrapper((HttpEntityEnclosingRequest) request);
            } else {
                wrapped = new RequestWrapper(request);
            }
            acceptEncodingInterceptor.process(wrapped, localContext);
            final HttpResponse response = backend.execute(target, wrapped, localContext);
            try {
                contentEncodingInterceptor.process(response, localContext);
                if (Boolean.TRUE.equals(localContext.getAttribute(ResponseContentEncoding.UNCOMPRESSED))) {
                    response.removeHeaders("Content-Length");
                    response.removeHeaders("Content-Encoding");
                    response.removeHeaders("Content-MD5");
                }
                return response;
            } catch (final HttpException ex) {
                EntityUtils.consume(response.getEntity());
                throw ex;
            } catch (final IOException ex) {
                EntityUtils.consume(response.getEntity());
                throw ex;
            } catch (final RuntimeException ex) {
                EntityUtils.consume(response.getEntity());
                throw ex;
            }
        } catch (final HttpException e) {
            throw new ClientProtocolException(e);
        }
    }

    @Override
    public <T> T execute(final HttpUriRequest request,
            final ResponseHandler<? extends T> responseHandler) throws IOException,
            ClientProtocolException {
        return execute(getHttpHost(request), request, responseHandler);
    }

    @Override
    public <T> T execute(final HttpUriRequest request,
            final ResponseHandler<? extends T> responseHandler, final HttpContext context)
            throws IOException, ClientProtocolException {
        return execute(getHttpHost(request), request, responseHandler, context);
    }

    @Override
    public <T> T execute(final HttpHost target, final HttpRequest request,
            final ResponseHandler<? extends T> responseHandler) throws IOException,
            ClientProtocolException {
        return execute(target, request, responseHandler, null);
    }

    @Override
    public <T> T execute(final HttpHost target, final HttpRequest request,
            final ResponseHandler<? extends T> responseHandler, final HttpContext context)
            throws IOException, ClientProtocolException {
        final HttpResponse response = execute(target, request, context);
        try {
            return responseHandler.handleResponse(response);
        } finally {
            final HttpEntity entity = response.getEntity();
            if (entity != null) {
                EntityUtils.consume(entity);
            }
        }
    }

}