Proxy.java revision cc0aad38f0e9a9096f0acb71dfd1f6a8ebc7d344 
1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.net;
18
19import org.apache.http.HttpHost;
20
21import android.content.ContentResolver;
22import android.content.Context;
23import android.os.SystemProperties;
24import android.provider.Settings;
25import android.util.Log;
26
27import java.net.InetAddress;
28import java.net.URI;
29import java.net.UnknownHostException;
30
31import junit.framework.Assert;
32
33/**
34 * A convenience class for accessing the user and default proxy
35 * settings.
36 */
37final public class Proxy {
38
39    // Set to true to enable extra debugging.
40    static final private boolean DEBUG = false;
41
42    static final public String PROXY_CHANGE_ACTION =
43        "android.intent.action.PROXY_CHANGE";
44
45    /**
46     * Return the proxy host set by the user.
47     * @param ctx A Context used to get the settings for the proxy host.
48     * @return String containing the host name. If the user did not set a host
49     *         name it returns the default host. A null value means that no
50     *         host is to be used.
51     */
52    static final public String getHost(Context ctx) {
53        ContentResolver contentResolver = ctx.getContentResolver();
54        Assert.assertNotNull(contentResolver);
55        String host = Settings.Secure.getString(
56                contentResolver,
57                Settings.Secure.HTTP_PROXY);
58        if (host != null) {
59            int i = host.indexOf(':');
60            if (i == -1) {
61                if (DEBUG) {
62                    Assert.assertTrue(host.length() == 0);
63                }
64                return null;
65            }
66            return host.substring(0, i);
67        }
68        return getDefaultHost();
69    }
70
71    /**
72     * Return the proxy port set by the user.
73     * @param ctx A Context used to get the settings for the proxy port.
74     * @return The port number to use or -1 if no proxy is to be used.
75     */
76    static final public int getPort(Context ctx) {
77        ContentResolver contentResolver = ctx.getContentResolver();
78        Assert.assertNotNull(contentResolver);
79        String host = Settings.Secure.getString(
80                contentResolver,
81                Settings.Secure.HTTP_PROXY);
82        if (host != null) {
83            int i = host.indexOf(':');
84            if (i == -1) {
85                if (DEBUG) {
86                    Assert.assertTrue(host.length() == 0);
87                }
88                return -1;
89            }
90            if (DEBUG) {
91                Assert.assertTrue(i < host.length());
92            }
93            return Integer.parseInt(host.substring(i+1));
94        }
95        return getDefaultPort();
96    }
97
98    /**
99     * Return the default proxy host specified by the carrier.
100     * @return String containing the host name or null if there is no proxy for
101     * this carrier.
102     */
103    static final public String getDefaultHost() {
104        String host = SystemProperties.get("net.gprs.http-proxy");
105        if (host != null) {
106            Uri u = Uri.parse(host);
107            host = u.getHost();
108            return host;
109        } else {
110            return null;
111        }
112    }
113
114    /**
115     * Return the default proxy port specified by the carrier.
116     * @return The port number to be used with the proxy host or -1 if there is
117     * no proxy for this carrier.
118     */
119    static final public int getDefaultPort() {
120        String host = SystemProperties.get("net.gprs.http-proxy");
121        if (host != null) {
122            Uri u = Uri.parse(host);
123            return u.getPort();
124        } else {
125            return -1;
126        }
127    }
128
129    /**
130     * Returns the preferred proxy to be used by clients. This is a wrapper
131     * around {@link android.net.Proxy#getHost()}. Currently no proxy will
132     * be returned for localhost or if the active network is Wi-Fi.
133     *
134     * @param context the context which will be passed to
135     * {@link android.net.Proxy#getHost()}
136     * @param url the target URL for the request
137     * @note Calling this method requires permission
138     * android.permission.ACCESS_NETWORK_STATE
139     * @return The preferred proxy to be used by clients, or null if there
140     * is no proxy.
141     *
142     * {@hide}
143     */
144    static final public HttpHost getPreferredHttpHost(Context context,
145            String url) {
146        if (!isLocalHost(url) && !isNetworkWifi(context)) {
147            final String proxyHost = Proxy.getHost(context);
148            if (proxyHost != null) {
149                return new HttpHost(proxyHost, Proxy.getPort(context), "http");
150            }
151        }
152
153        return null;
154    }
155
156    static final private boolean isLocalHost(String url) {
157        if (url == null) {
158            return false;
159        }
160
161        try {
162            final URI uri = URI.create(url);
163            final String host = uri.getHost();
164            if (host != null) {
165                if (host.equalsIgnoreCase("localhost")) {
166                    return true;
167                }
168                if (InetAddress.getByName(host).isLoopbackAddress()) {
169                    return true;
170                }
171            }
172        } catch (UnknownHostException uex) {
173            // Ignore (INetworkSystem.ipStringToByteArray)
174        } catch (IllegalArgumentException iex) {
175            // Ignore (URI.create)
176        }
177
178        return false;
179    }
180
181    static final private boolean isNetworkWifi(Context context) {
182        if (context == null) {
183            return false;
184        }
185
186        final ConnectivityManager connectivity = (ConnectivityManager)
187            context.getSystemService(Context.CONNECTIVITY_SERVICE);
188        if (connectivity != null) {
189            final NetworkInfo info = connectivity.getActiveNetworkInfo();
190            if (info != null &&
191                    info.getType() == ConnectivityManager.TYPE_WIFI) {
192                return true;
193            }
194        }
195
196        return false;
197    }
198};
199