[Android]正确地访问网络资源----Proxy的使用

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



本文内容归CSDN博客博主Sodino
所有

转载请注明出处:http://blog.csdn.net/sodino/archive/2011/04/05/6302313.aspx