android开发socket编程之udp发送实例分析

package test.soket; //import com.test_button.R; import java.io.DataOutputStream; import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; import java.net.Socket; import java.net.SocketException; import java.net.UnknownHostException; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; public class test_socket extends Activity {  public static TextView show;  public static Button press;  public static boolean flag;  private static final int MAX_DATA_PACKET_LENGTH = 40;  private byte[] buffer = new byte[MAX_DATA_PACKET_LENGTH];  private DatagramPacket dataPacket;  private DatagramSocket udpSocket;  /** Called when the activity is first created. */  @Override  public void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   setContentView(R.layout.main);   //开辟控件空间   show = (TextView)findViewById(R.id.editText1);   press = (Button)findViewById(R.id.button1);   flag = false;   //soket_send thread = new soket_send();   //thread.init();   //thread.start();   try   {    udpSocket = new DatagramSocket(5554);   }   catch (SocketException e)   {    // TODO Auto-generated catch block    e.printStackTrace();   }   dataPacket = new DatagramPacket(buffer, MAX_DATA_PACKET_LENGTH);   String str = "hello,jdh"; //这是要传输的数据   byte out [] = str.getBytes(); //把传输内容分解成字节   dataPacket.setData(out);   dataPacket.setLength(out.length);   dataPacket.setPort(5554);   try   {    InetAddress broadcastAddr = InetAddress.getByName("192.168.0.248");    dataPacket.setAddress(broadcastAddr);    udpSocket.send(dataPacket);   }   catch (IOException e)   {    // TODO Auto-generated catch block    e.printStackTrace();   }       press.setOnClickListener(new Button.OnClickListener()   {    @Override    public void onClick(View v)    {     flag = true;     /*     String str = "hello,jdh"; //这是要传输的数据     byte out [] = str.getBytes(); //把传输内容分解成字节     dataPacket.setData(out);     dataPacket.setLength(out.length);     */     //获得输入框文本     CharSequence str =test_socket.show.getText();     byte out[] = str.toString().getBytes();     dataPacket.setData(out);     dataPacket.setLength(out.length);     try     {      InetAddress broadcastAddr = InetAddress.getByName("192.168.0.248");      dataPacket.setAddress(broadcastAddr);      udpSocket.send(dataPacket);     }     catch (IOException e)     {      // TODO Auto-generated catch block      e.printStackTrace();     }    }   });  } }