Java tutorial
/* * 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.android.volley.stack; import android.text.TextUtils; import com.android.volley.AuthFailureError; import com.android.volley.Request; import com.android.volley.Request.Method; import org.apache.http.*; import org.apache.http.entity.BasicHttpEntity; import org.apache.http.message.BasicHeader; import org.apache.http.message.BasicHttpResponse; import org.apache.http.message.BasicStatusLine; import org.apache.http.protocol.HTTP; import javax.net.ssl.HttpsURLConnection; import javax.net.ssl.SSLSocketFactory; import java.io.DataOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; import java.util.HashMap; import java.util.List; import java.util.Map.Entry; /** * An {@link HttpStack} based on {@link HttpURLConnection}. */ public class HurlStack implements HttpStack { private String mUserAgent; private final SSLSocketFactory mSslSocketFactory; /** * @param sslSocketFactory SSL factory to use for HTTPS connections */ public HurlStack(String userAgent, SSLSocketFactory sslSocketFactory) { mSslSocketFactory = sslSocketFactory; mUserAgent = userAgent; } public HurlStack(String userAgent) { this(userAgent, null); } @Override public HttpResponse performRequest(Request<?> request) throws IOException, AuthFailureError { HashMap<String, String> map = new HashMap<String, String>(); if (!TextUtils.isEmpty(mUserAgent)) { map.put(HTTP.USER_AGENT, mUserAgent); } map.putAll(request.getHeaders()); URL parsedUrl = new URL(request.getUrl()); HttpURLConnection connection = openConnection(parsedUrl, request); for (String headerName : map.keySet()) { connection.addRequestProperty(headerName, map.get(headerName)); } setConnectionParametersForRequest(connection, request); int responseCode = connection.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(new ProtocolVersion("HTTP", 1, 1), connection.getResponseCode(), connection.getResponseMessage()); BasicHttpResponse response = new BasicHttpResponse(responseStatus); response.setEntity(entityFromConnection(connection)); for (Entry<String, List<String>> header : connection.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}. * @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}. */ private HttpURLConnection createConnection(URL url) throws IOException { return (HttpURLConnection) url.openConnection(); } /** * Opens an {@link HttpURLConnection} with parameters. * @return an open connection */ private HttpURLConnection openConnection(URL url, Request<?> request) throws IOException { HttpURLConnection connection = createConnection(url); int timeoutMs = request.getTimeoutMs(); connection.setConnectTimeout(timeoutMs); connection.setReadTimeout(timeoutMs); connection.setUseCaches(false); connection.setDoInput(true); // use caller-provided custom SslSocketFactory, if any, for HTTPS if ("https".equals(url.getProtocol()) && mSslSocketFactory != null) { ((HttpsURLConnection) connection).setSSLSocketFactory(mSslSocketFactory); } return connection; } private static void setConnectionParametersForRequest(HttpURLConnection connection, Request<?> request) throws IOException, AuthFailureError { switch (request.getMethod()) { case Method.GET: // Not necessary to set the request method because connection defaults to GET but // being explicit here. connection.setRequestMethod("GET"); break; case Method.DELETE: connection.setRequestMethod("DELETE"); break; case Method.POST: connection.setRequestMethod("POST"); addBodyIfExists(connection, request); break; case Method.PUT: connection.setRequestMethod("PUT"); addBodyIfExists(connection, request); break; case Method.HEAD: connection.setRequestMethod("HEAD"); break; case Method.OPTIONS: connection.setRequestMethod("OPTIONS"); break; case Method.TRACE: connection.setRequestMethod("TRACE"); break; case Method.PATCH: addBodyIfExists(connection, request); connection.setRequestMethod("PATCH"); break; default: throw new IllegalStateException("Unknown method type."); } } private static void addBodyIfExists(HttpURLConnection connection, Request<?> request) throws IOException, AuthFailureError { byte[] body = request.getBody(); if (body != null) { connection.setDoOutput(true); connection.addRequestProperty(HTTP.CONTENT_TYPE, request.getBodyContentType()); DataOutputStream out = new DataOutputStream(connection.getOutputStream()); out.write(body); out.close(); } } }