com.snda.mymarket.providers.downloads.HurlStack.java Source code

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Here is the source code for com.snda.mymarket.providers.downloads.HurlStack.java

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/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * 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 com.snda.mymarket.providers.downloads;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map.Entry;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.ProtocolVersion;
import org.apache.http.StatusLine;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.entity.BasicHttpEntity;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicHttpResponse;
import org.apache.http.message.BasicStatusLine;

/**
 * An {@link HttpStack} based on {@link HttpURLConnection}.
 */
public class HurlStack implements HttpStack {

    private HttpURLConnection client;

    /**
     * An interface for transforming URLs before use.
     */
    public interface UrlRewriter {
        /**
         * Returns a URL to use instead of the provided one, or null to indicate
         * this URL should not be used at all.
         */
        public String rewriteUrl(String originalUrl);
    }

    private final UrlRewriter mUrlRewriter;

    public HurlStack() {
        this(null);
    }

    /**
     * @param urlRewriter Rewriter to use for request URLs
     */
    public HurlStack(UrlRewriter urlRewriter) {
        mUrlRewriter = urlRewriter;
    }

    @Override
    public HttpResponse performRequest(HttpUriRequest request) throws IOException {
        String url = request.getURI().toString();

        if (mUrlRewriter != null) {
            String rewritten = mUrlRewriter.rewriteUrl(url);
            if (rewritten == null) {
                throw new IOException("URL blocked by rewriter: " + url);
            }
            url = rewritten;
        }
        URL parsedUrl = new URL(url);
        client = openConnection(parsedUrl, request);
        for (Header headerName : request.getAllHeaders()) {
            client.addRequestProperty(headerName.getName(), headerName.getValue());
        }
        client.setRequestMethod("GET");
        // Initialize HttpResponse with data from the HttpURLConnection.
        ProtocolVersion protocolVersion = new ProtocolVersion("HTTP", 1, 1);
        int responseCode = client.getResponseCode();
        if (responseCode == -1) {
            // -1 is returned by getResponseCode() if the response code could not be retrieved.
            // Signal to the caller that something was wrong with the connection.
            throw new IOException("Could not retrieve response code from HttpUrlConnection.");
        }
        StatusLine responseStatus = new BasicStatusLine(protocolVersion, client.getResponseCode(),
                client.getResponseMessage());
        BasicHttpResponse response = new BasicHttpResponse(responseStatus);
        response.setEntity(entityFromConnection(client));
        for (Entry<String, List<String>> header : client.getHeaderFields().entrySet()) {
            if (header.getKey() != null) {
                Header h = new BasicHeader(header.getKey(), header.getValue().get(0));
                response.addHeader(h);
            }
        }
        return response;
    }

    /**
     * Initializes an {@link HttpEntity} from the given {@link HttpURLConnection}.
     * @param connection
     * @return an HttpEntity populated with data from <code>connection</code>.
     */
    private static HttpEntity entityFromConnection(HttpURLConnection connection) {
        BasicHttpEntity entity = new BasicHttpEntity();
        InputStream inputStream;
        try {
            inputStream = connection.getInputStream();
        } catch (IOException ioe) {
            inputStream = connection.getErrorStream();
        }
        entity.setContent(inputStream);
        entity.setContentLength(connection.getContentLength());
        entity.setContentEncoding(connection.getContentEncoding());
        entity.setContentType(connection.getContentType());
        return entity;
    }

    /**
     * Create an {@link HttpURLConnection} for the specified {@code url}.
     */
    protected HttpURLConnection createConnection(URL url) throws IOException {
        return (HttpURLConnection) url.openConnection();
    }

    /**
     * Opens an {@link HttpURLConnection} with parameters.
     * @param url
     * @return an open connection
     * @throws IOException
     */
    private HttpURLConnection openConnection(URL url, HttpUriRequest request) throws IOException {
        HttpURLConnection connection = createConnection(url);

        int timeoutMs = TIMEOUT_MSECONDES;
        connection.setConnectTimeout(timeoutMs);
        connection.setReadTimeout(timeoutMs);
        connection.setUseCaches(false);
        connection.setDoInput(true);

        return connection;
    }

    @Override
    public void close() throws IOException {
        if (client != null) {
            client.disconnect();
        }
    }
}