【发布时间】：2012-03-12 06:37:23
【问题描述】：
我想创建一个用于连接多个 android 设备的应用程序。这里能够从设备（使用 Wifi 网络）连接到另一个设备（3G 网络）。我需要从使用 3G 网络的设备连接到使用 Wifi 网络的设备。如何我可以将使用 3G 网络的设备连接到 WiFi 网络吗？
Server Side:
包 com.server.org;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.widget.TextView;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.util.Enumeration;
public class ServerActivity extends Activity {
private TextView serverStatus;
// default ip
public static String SERVERIP = "10.0.2.15";
// designate a port
public static final int SERVERPORT = 9191;
private Handler handler = new Handler();
private ServerSocket serverSocket;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
serverStatus = (TextView) findViewById(R.id.server_status);
SERVERIP = getLocalIpAddress();
Thread fst = new Thread(new ServerThread());
fst.start();
}
public class ServerThread implements Runnable {
public void run() {
try {
if (SERVERIP != null) {
handler.post(new Runnable() {
public void run() {
serverStatus.setText("Listening on IP: " + SERVERIP);
}
});
serverSocket = new ServerSocket(SERVERPORT);
while (true) {
// listen for incoming clients
Socket client = serverSocket.accept();
handler.post(new Runnable() {
public void run() {
serverStatus.setText("Connected.");
}
});
try {
BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
Log.d("ServerActivity", line);
handler.post(new Runnable() {
public void run() {
// do whatever you want to the front end
// this is where you can be creative
}
});
}
break;
} catch (Exception e) {
handler.post(new Runnable() {
public void run() {
serverStatus.setText("Oops. Connection interrupted. Please reconnect your phones.");
}
});
e.printStackTrace();
}
}
} else {
handler.post(new Runnable() {
public void run() {
serverStatus.setText("Couldn't detect internet connection.");
}
});
}
} catch (Exception e) {
handler.post(new Runnable() {
public void run() {
serverStatus.setText("Error");
}
});
e.printStackTrace();
}
}
}
// gets the ip address of your phone's network
private String getLocalIpAddress() {
try {
for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
NetworkInterface intf = en.nextElement();
for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) {
InetAddress inetAddress = enumIpAddr.nextElement();
if (!inetAddress.isLoopbackAddress()) { return inetAddress.getHostAddress().toString(); }
}
}
} catch (SocketException ex) {
Log.e("ServerActivity", ex.toString());
}
return null;
}
@Override
protected void onStop() {
super.onStop();
try {
// make sure you close the socket upon exiting
serverSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Client Side:
包 com.client.org;
import java.io.BufferedWriter;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class ClientActivity extends Activity {
private EditText serverIp;
private Button connectPhones;
private String serverIpAddress = "";
private boolean connected = false;
private Handler handler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
serverIp = (EditText) findViewById(R.id.server_ip);
connectPhones = (Button) findViewById(R.id.connect_phones);
connectPhones.setOnClickListener(connectListener);
}
private OnClickListener connectListener = new OnClickListener() {
@Override
public void onClick(View v) {
if (!connected) {
serverIpAddress = serverIp.getText().toString();
if (!serverIpAddress.equals("")) {
Thread cThread = new Thread(new ClientThread());
cThread.start();
}
}
}
};
public class ClientThread implements Runnable {
public void run() {
try {
InetAddress serverAddr = InetAddress.getByName(serverIpAddress);
Log.d("ClientActivity", "C: Connecting...");
int SERVERPORT = 9191;
Socket socket = new Socket(serverAddr,SERVERPORT );
connected = true;
while (connected) {
try {
Log.d("ClientActivity", "C: Sending command.");
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket
.getOutputStream())), true);
// where you issue the commands
out.println("Hey Server!");
Log.d("ClientActivity", "C: Sent.");
} catch (Exception e) {
Log.e("ClientActivity", "S: Error", e);
}
}
socket.close();
Log.d("ClientActivity", "C: Closed.");
} catch (Exception e) {
Log.e("ClientActivity", "C: Error", e);
connected = false;
}
}
}
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标签： android