正确地访问网络资源----Proxy的使用

http://blog.csdn.net/sodino/article/details/6302313

 

天朝有很多独特的东西，今天要涉及到的是CMWAP与CMNET。

 

现在仍有许多Android手机用的是CMWAP连接网络的，如果只是简单滴使用URL.openConnection()开启一个HttpURLConnection，则会发现有一个UnknownHostException被抛出。唉...身为悲剧的程序员，就要开始解决这种bug了。

 

Sodino还发现一个现象，为什么自己的程序会崩掉，而Google浏览器就不会呢？与国产软件不同，国产软件身处天朝的软硬件环境下成长，可能会将代理IP（10.0.0.172）写进程序中，Sodino也确实反编译了几个程序后发现他们也是这样做来保持CMWAP下的正常联接。但是，Google浏览器可不是国人写的，那帮老外可不考虑天朝还有个CMWAP。那他们是如何保证网络的正常联接呢？一番鼓捣下，有了以下代码，可以在WIFI/CMWAP/CMNET/CTNET下正常访问网络，附带如何使用ping使用。

先上效果图：

 

 

package lab.sodino.network;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.InetSocketAddress;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.UnknownHostException;
import android.app.Activity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class NetworkAct extends Activity {
    public static final int CLEAR_TEXT = 0;
    public static final int APPEND_TEXT = 1;
    private TextView txtInfo;
    private Button btnPing;
    private Button btnConnect;
    private Button btnClear;
    private BtnListener btnListener;
    private Handler handler = new Handler() {
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case APPEND_TEXT:
                String content = msg.obj.toString();
                txtInfo.setText("/n" + content);
                break;
            case CLEAR_TEXT:
                txtInfo.setText("");
                break;
            }
        }
    };
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btnListener = new BtnListener();
        txtInfo = (TextView) findViewById(R.id.txtInfo);
        btnPing = (Button) findViewById(R.id.btnPing);
        btnPing.setOnClickListener(btnListener);
        btnConnect = (Button) findViewById(R.id.btnConnect);
        btnConnect.setOnClickListener(btnListener);
        btnClear = (Button) findViewById(R.id.btnClear);
        btnClear.setOnClickListener(btnListener);
    }
    /**
     * @param param
     *            指定的域名如(www.google.com)或IP地址。
     */
    private void doPing(final String param) {
        new Thread() {
            public void run() {
                String line = "";
                InputStream is = null;
                try {
                    line = "/nping -c 1 " + param;
                    // -c 1:表示ping的次数为1次。
                    Process p = Runtime.getRuntime().exec("ping -c 1 www.google.com");
                    // 等待该命令执行完毕。
                    int status = p.waitFor();
                    if (status == 0) {
                        // 正常退出
                        line += "Pass";
                    } else {
                        // 异常退出
                        line += "Fail: Host unreachable";
                    }
                    is = p.getInputStream();
                    byte[] data = new byte[is.available()];
                    is.read(data);
                    line += "/n" + new String(data);
                } catch (UnknownHostException e) {
                    line += "Fail: Unknown Host";
                } catch (IOException e) {
                    line += "Fail: IOException";
                } catch (InterruptedException e) {
                    line += "Fail: InterruptedException";
                }
                Message msg = new Message();
                msg.what = APPEND_TEXT;
                msg.obj = line;
                handler.sendMessage(msg);
            }
        }.start();
    }
    private void go2Network() {
        new Thread() {
            public void run() {
                String line = "";
                URL url = null;
                HttpURLConnection httpConn = null;
                InputStream is = null;
                try {
                    url = new URL("http://www.sodino.com/index.html");
                    // Log.d("ANDROID_LAB", "Protocol=" + new
                    // URL("https://www.sodino.com").getProtocol());
                    // 需要android.permission.ACCESS_NETWORK_STATE
                    NetworkInfo networkInfo = ((ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE))
                            .getActiveNetworkInfo();
                    // 如果是使用的运营商网络
                    if (networkInfo.getType() == ConnectivityManager.TYPE_MOBILE) {
                        // 获取默认代理主机ip
                        String host = android.net.Proxy.getDefaultHost();
                        // 获取端口
                        int port = android.net.Proxy.getDefaultPort();
                        if (host != null && port != -1) {
                            line += "/nhost[" + host + "] port[" + port + "]";
                            // 封装代理連接主机IP与端口号。
                            InetSocketAddress inetAddress = new InetSocketAddress(host, port);
                            // 根据URL链接获取代理类型，本链接适用于TYPE.HTTP
                            java.net.Proxy.Type proxyType = java.net.Proxy.Type.valueOf(url
                                    .getProtocol().toUpperCase());
                            java.net.Proxy javaProxy = new java.net.Proxy(proxyType, inetAddress);
                            httpConn = (HttpURLConnection) url.openConnection(javaProxy);
                        } else {
                            httpConn = (HttpURLConnection) url.openConnection();
                        }
                    } else {
                        httpConn = (HttpURLConnection) url.openConnection();
                    }
                    httpConn.connect();
                    int length = httpConn.getContentLength();
                    byte[] data = new byte[length];
                    String encoding = httpConn.getContentEncoding();
                    line += "/nlength=" + length + " encoding=" + encoding;
                    is = httpConn.getInputStream();
                    is.read(data);
                    String content = null;
                    if (encoding != null) {
                        content = new String(data, encoding);
                    } else {
                        content = new String(data);
                    }
                    line += "/nContent[/n" + content + "/n]";
                    Message msg = new Message();
                    msg.what = APPEND_TEXT;
                    msg.obj = line;
                    handler.sendMessage(msg);
                } catch (IOException ie) {
                    ie.printStackTrace();
                } finally {
                    try {
                        if (is != null) {
                            is.close();
                        }
                        if (httpConn != null) {
                            httpConn.disconnect();
                        }
                    } catch (IOException ie) {
                        ie.printStackTrace();
                    }
                }
            }
        }.start();
    }
    class BtnListener implements Button.OnClickListener {
        public void onClick(View view) {
            if (view == btnPing) {
                // doPing("www.google.com");
                doPing("10.0.0.172");
            } else if (view == btnConnect) {
                go2Network();
            } else if (view == btnClear) {
                Message msg = new Message();
                msg.what = CLEAR_TEXT;
                handler.sendMessage(msg);
            }
        }
    }
}

 

 

如此，悲剧的程序员解决了不同网络状态下如何保证正常链接的问题。

最后补充下：Android手机在CMWAP上要能够正常上网，除了设置一大堆代理数据外，还需进入拨号器下按"*#*#4636#*#*"→Phone Information下拉到最后后有个“Toggle DNS Check”，将其设置为allow