org.callimachusproject.client.GUnzipInterceptor.java Source code

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Here is the source code for org.callimachusproject.client.GUnzipInterceptor.java

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/*
 * Copyright (c) 2013 3 Round Stones Inc., Some Rights Reserved
 *
 * 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.callimachusproject.client;

import java.io.IOException;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpCoreContext;
import org.callimachusproject.util.DomainNameSystemResolver;

public class GUnzipInterceptor implements HttpResponseInterceptor {
    private static final String hostname = DomainNameSystemResolver.getInstance().getLocalHostName();
    private static final String WARN_214 = "214 " + hostname + " \"Transformation applied\"";

    @Override
    public void process(HttpResponse resp, HttpContext context) throws HttpException, IOException {
        HttpRequest req = (HttpRequest) context.getAttribute(HttpCoreContext.HTTP_REQUEST);
        HttpEntity entity = resp.getEntity();
        if (entity == null)
            return;
        Header cache = req.getFirstHeader("Cache-Control");
        if (cache != null && cache.getValue().contains("no-transform"))
            return;
        Header encoding = resp.getFirstHeader("Content-Encoding");
        if (encoding != null && "gzip".equals(encoding.getValue())) {
            resp.removeHeaders("Content-MD5");
            resp.removeHeaders("Content-Length");
            resp.setHeader("Content-Encoding", "identity");
            resp.addHeader("Warning", WARN_214);
            resp.setEntity(gunzip(entity));
        }
    }

    private HttpEntity gunzip(HttpEntity entity) {
        if (entity instanceof GZipEntity)
            return ((GZipEntity) entity).getEntityDelegate();
        if (entity instanceof CloseableEntity) {
            CloseableEntity centity = (CloseableEntity) entity;
            centity.setEntityDelegate(gunzip(centity.getEntityDelegate()));
            return centity;
        }
        return new GUnzipEntity(entity);
    }
}