at.bitfire.davdroid.webdav.GzipDecompressingEntity.java Source code

Introduction

Here is the source code for at.bitfire.davdroid.webdav.GzipDecompressingEntity.java

Source

/*******************************************************************************
 * Copyright (c) 2014 Richard Hirner (bitfire web engineering).
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     Richard Hirner (bitfire web engineering) - initial API and implementation
 ******************************************************************************/
package at.bitfire.davdroid.webdav;

import java.io.IOException;
import java.io.InputStream;
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.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.entity.HttpEntityWrapper;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.protocol.HttpContext;

class GzipDecompressingEntity extends HttpEntityWrapper {
    public GzipDecompressingEntity(final HttpEntity entity) {
        super(entity);
    }

    @Override
    public InputStream getContent() throws IOException, IllegalStateException {

        // the wrapped entity's getContent() decides about repeatability
        InputStream wrappedin = wrappedEntity.getContent();

        return new GZIPInputStream(wrappedin);
    }

    @Override
    public long getContentLength() {
        // length of ungzipped content is not known
        return -1;
    }

    public static void enable(DefaultHttpClient client) {
        client.addRequestInterceptor(new HttpRequestInterceptor() {
            @Override
            public void process(HttpRequest request, HttpContext context) throws HttpException, IOException {
                if (!request.containsHeader("Accept-Encoding"))
                    request.addHeader("Accept-Encoding", "gzip");
            }
        });
        client.addResponseInterceptor(new HttpResponseInterceptor() {
            @Override
            public void process(HttpResponse response, HttpContext context) throws HttpException, IOException {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    Header ceheader = entity.getContentEncoding();
                    if (ceheader != null) {
                        HeaderElement[] codecs = ceheader.getElements();
                        for (int i = 0; i < codecs.length; i++) {
                            if (codecs[i].getName().equalsIgnoreCase("gzip")) {
                                response.setEntity(new GzipDecompressingEntity(response.getEntity()));
                                return;
                            }
                        }
                    }
                }
            }
        });
    }
}