/* * Copyright (C) 2008 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.server.location; import android.content.Context; import android.net.Proxy; import android.net.http.AndroidHttpClient; import android.util.Config; import android.util.Log; import org.apache.http.HttpEntity; import org.apache.http.HttpHost; import org.apache.http.HttpResponse; import org.apache.http.StatusLine; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpUriRequest; import org.apache.http.conn.params.ConnRouteParams; import java.io.DataInputStream; import java.io.IOException; import java.util.Properties; import java.util.Random; /** * A class for downloading GPS XTRA data. * * {@hide} */ public class GpsXtraDownloader { private static final String TAG = "GpsXtraDownloader"; static final boolean DEBUG = false; private Context mContext; private String[] mXtraServers; // to load balance our server requests private int mNextServerIndex; GpsXtraDownloader(Context context, Properties properties) { mContext = context; // read XTRA servers from the Properties object int count = 0; String server1 = properties.getProperty("XTRA_SERVER_1"); String server2 = properties.getProperty("XTRA_SERVER_2"); String server3 = properties.getProperty("XTRA_SERVER_3"); if (server1 != null) count++; if (server2 != null) count++; if (server3 != null) count++; if (count == 0) { Log.e(TAG, "No XTRA servers were specified in the GPS configuration"); return; } else { mXtraServers = new String[count]; count = 0; if (server1 != null) mXtraServers[count++] = server1; if (server2 != null) mXtraServers[count++] = server2; if (server3 != null) mXtraServers[count++] = server3; // randomize first server Random random = new Random(); mNextServerIndex = random.nextInt(count); } } byte[] downloadXtraData() { String proxyHost = Proxy.getHost(mContext); int proxyPort = Proxy.getPort(mContext); boolean useProxy = (proxyHost != null && proxyPort != -1); byte[] result = null; int startIndex = mNextServerIndex; if (mXtraServers == null) { return null; } // load balance our requests among the available servers while (result == null) { result = doDownload(mXtraServers[mNextServerIndex], useProxy, proxyHost, proxyPort); // increment mNextServerIndex and wrap around if necessary mNextServerIndex++; if (mNextServerIndex == mXtraServers.length) { mNextServerIndex = 0; } // break if we have tried all the servers if (mNextServerIndex == startIndex) break; } return result; } protected static byte[] doDownload(String url, boolean isProxySet, String proxyHost, int proxyPort) { if (DEBUG) Log.d(TAG, "Downloading XTRA data from " + url); AndroidHttpClient client = null; try { client = AndroidHttpClient.newInstance("Android"); HttpUriRequest req = new HttpGet(url); if (isProxySet) { HttpHost proxy = new HttpHost(proxyHost, proxyPort); ConnRouteParams.setDefaultProxy(req.getParams(), proxy); } req.addHeader( "Accept", "*/*, application/vnd.wap.mms-message, application/vnd.wap.sic"); req.addHeader( "x-wap-profile", "http://www.openmobilealliance.org/tech/profiles/UAPROF/ccppschema-20021212#"); HttpResponse response = client.execute(req); StatusLine status = response.getStatusLine(); if (status.getStatusCode() != 200) { // HTTP 200 is success. if (DEBUG) Log.d(TAG, "HTTP error: " + status.getReasonPhrase()); return null; } HttpEntity entity = response.getEntity(); byte[] body = null; if (entity != null) { try { if (entity.getContentLength() > 0) { body = new byte[(int) entity.getContentLength()]; DataInputStream dis = new DataInputStream(entity.getContent()); try { dis.readFully(body); } finally { try { dis.close(); } catch (IOException e) { Log.e(TAG, "Unexpected IOException.", e); } } } } finally { if (entity != null) { entity.consumeContent(); } } } return body; } catch (Exception e) { if (DEBUG) Log.d(TAG, "error " + e); } finally { if (client != null) { client.close(); } } return null; } }