Java tutorial
/* * Copyright (C) 2007 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.lemi.mario.download.utils; import android.content.ContentResolver; import android.content.Context; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.net.Uri; import android.provider.Settings; import junit.framework.Assert; import org.apache.http.HttpHost; import java.lang.reflect.Method; import java.net.URI; /** * A convenience class for accessing the user and default proxy * settings. */ final public class Proxy { // Set to true to enable extra debugging. static final private boolean DEBUG = false; static final public String PROXY_CHANGE_ACTION = "android.intent.action.PROXY_CHANGE"; private static HttpHost proxyHost; /** * Return the proxy host set by the user. * * @param ctx A Context used to get the settings for the proxy host. * @return String containing the host name. If the user did not set a host * name it returns the default host. A null value means that no * host is to be used. */ static final public String getHost(Context ctx) { ContentResolver contentResolver = ctx.getContentResolver(); Assert.assertNotNull(contentResolver); String host = Settings.Secure.getString(contentResolver, Settings.Secure.HTTP_PROXY); if (host != null) { int i = host.indexOf(':'); if (i == -1) { if (DEBUG) { Assert.assertTrue(host.length() == 0); } return null; } return host.substring(0, i); } return getDefaultHost(); } /** * Return the proxy port set by the user. * * @param ctx A Context used to get the settings for the proxy port. * @return The port number to use or -1 if no proxy is to be used. */ static final public int getPort(Context ctx) { ContentResolver contentResolver = ctx.getContentResolver(); Assert.assertNotNull(contentResolver); String host = Settings.Secure.getString(contentResolver, Settings.Secure.HTTP_PROXY); if (host != null) { int i = host.indexOf(':'); if (i == -1) { if (DEBUG) { Assert.assertTrue(host.length() == 0); } return -1; } if (DEBUG) { Assert.assertTrue(i < host.length()); } return Integer.parseInt(host.substring(i + 1)); } return getDefaultPort(); } /** * Return the default proxy host specified by the carrier. * * @return String containing the host name or null if there is no proxy for * this carrier. */ static final public String getDefaultHost() { String host = null; // use reflection to invoke the method try { Class clazz = Class.forName("android.os.SystemProperties"); Method getMethod = clazz.getMethod("get", new Class[] { String.class }); host = (String) getMethod.invoke(clazz, new Object[] { "net.gprs.http-proxy" }); } catch (Exception e) { e.printStackTrace(); } // String host = SystemProperties.get("net.gprs.http-proxy"); if (host != null) { Uri u = Uri.parse(host); host = u.getHost(); return host; } else { return null; } } /** * Return the default proxy port specified by the carrier. * * @return The port number to be used with the proxy host or -1 if there is * no proxy for this carrier. */ static final public int getDefaultPort() { String host = null; // use reflection to invoke the method try { Class clazz = Class.forName("android.os.SystemProperties"); Method getMethod = clazz.getMethod("get", new Class[] { String.class }); host = (String) getMethod.invoke(clazz, new Object[] { "net.gprs.http-proxy" }); } catch (Exception e) { e.printStackTrace(); } // String host = SystemProperties.get("net.gprs.http-proxy"); if (host != null) { Uri u = Uri.parse(host); return u.getPort(); } else { return -1; } } /** * Returns the preferred proxy to be used by clients. This is a wrapper * around {@link android.net.Proxy#getHost()}. Currently no proxy will * be returned for localhost or if the active network is Wi-Fi. * * @param context the context which will be passed to {@link android.net.Proxy#getHost()} * @param url the target URL for the request * @note Calling this method requires permission * android.permission.ACCESS_NETWORK_STATE * @return The preferred proxy to be used by clients, or null if there * is no proxy. * * {@hide} */ static final public HttpHost getPreferredHttpHost(Context context, String url) { if (proxyHost != null) { return proxyHost; } if (!isLocalHost(url) && !isNetworkWifi(context)) { final String proxyHost = Proxy.getHost(context); if (proxyHost != null) { return new HttpHost(proxyHost, Proxy.getPort(context), "http"); } } return null; } static final private boolean isLocalHost(String url) { if (url == null) { return false; } try { final URI uri = URI.create(url); final String host = uri.getHost(); if (host != null) { // TODO: InetAddress.isLoopbackAddress should be used to check // for localhost. However no public factory methods exist which // can be used without triggering DNS lookup if host is not localhost. if (host.equalsIgnoreCase("localhost") || host.equals("127.0.0.1") || host.equals("[::1]")) { return true; } } } catch (IllegalArgumentException iex) { // Ignore (URI.create) } return false; } static final private boolean isNetworkWifi(Context context) { if (context == null) { return false; } final ConnectivityManager connectivity = (ConnectivityManager) context .getSystemService(Context.CONNECTIVITY_SERVICE); if (connectivity != null) { final NetworkInfo info = connectivity.getActiveNetworkInfo(); if (info != null && info.getType() == ConnectivityManager.TYPE_WIFI) { return true; } } return false; } public static void setProxyHttpHost(HttpHost host) { proxyHost = host; } }