1 files changed, 171 insertions, 0 deletions
diff --git a/services/java/com/android/server/location/GpsXtraDownloader.java b/services/java/com/android/server/location/GpsXtraDownloader.java
new file mode 100644
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--- /dev/null
+++ b/services/java/com/android/server/location/GpsXtraDownloader.java
@@ -0,0 +1,171 @@
+/*
+ * 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";
+    
+    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 (Config.LOGD) 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 (Config.LOGD) 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 (Config.LOGD) Log.d(TAG, "error " + e);
+        } finally {
+            if (client != null) {
+                client.close();
+            }
+        }
+        return null;
+    }
+
+}