Simple UDP Client instance implemented by Android programming

This article gives an example of how Android can be programmed to implement simple UDP Client.Share it for your reference, as follows:

The code passed debugging in 4.2.2

1. Remember the weighted limit

<uses-permission android:name="android.permission.INTERNET"/>

Note: After Android 4.0, socket communication cannot occur on the main thread, otherwise an exception will be thrown.

2. Code

MainActivity.java:

package mao.example.quicksend;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import android.view.View;
public class MainActivity extends Activity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    InitUI();
    // Get Button object 
    Button btnConnect = (Button) findViewById(R.id.buttonConnect);
    btnConnect.setOnClickListener(new Button.OnClickListener() {
      public void onClick(View v)
      {
        // Handle events here 
        //ConnectServer();
        //UDPClient udpET = new UDPClient("192.168.0.14","123");
        //udpET.start();
        //DisplayToast(" Clicked \" Connect \" Button ");
      }
    });
    // Send out Button
    btnConnect = (Button) findViewById(R.id.buttonSend);
    btnConnect.setOnClickListener(new Button.OnClickListener() {
      public void onClick(View v)
      {
        // Handle events here 
        SendText();
      }
    });
  }
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
      return true;
    }
    return super.onOptionsItemSelected(item);
  }
  /*  display Toast */
  public void DisplayToast(String str)
  {
    Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
  }
  public void InitUI()
  {
    TextView text=(TextView)findViewById(R.id.editTextIP);
    text.setText("192.168.0.14");
    text = (TextView)findViewById(R.id.editTextFilePath);
    text.setText("Udp Client Send Test");
  }
  // connect server
  public void SendText() 
  {
    TextView editIP=(TextView)findViewById(R.id.editTextIP);
    TextView editText=(TextView)findViewById(R.id.editTextFilePath);
    String message = editText.getText().toString() + "\r\n"; 
    UDPClient udpET = new UDPClient(editIP.getText().toString(), message);
    udpET.start();
  }
}

UDPClient.java:

package mao.example.quicksend;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.lang.String;
public class UDPClient extends Thread{
  public String m_serverIP;
  public String m_text;
  public UDPClient(String strServerIP, String strText)
  {
    m_serverIP = strServerIP;
    m_text = strText;
  }
  @Override
  public void run() {
    // TODO Auto-generated method stub
    int TIMEOUT = 3000;
    int servPort = 8800;
    byte[] bytesToSend = m_text.getBytes();//"test_client".getBytes();
    try {
      InetAddress serverAddress = InetAddress.getByName(m_serverIP);
      DatagramSocket socket = new DatagramSocket();
      socket.setSoTimeout(TIMEOUT);
      DatagramPacket sendPacket = new DatagramPacket(bytesToSend,bytesToSend.length,serverAddress,servPort);
      socket.send(sendPacket);
      socket.close();
    } catch (SocketException e){
      e.printStackTrace();
    }catch(IOException e){
      e.printStackTrace();
    }
  }
}

3. activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:id="@+id/LinearLayout1"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"
  android:paddingBottom="@dimen/activity_vertical_margin"
  android:paddingLeft="@dimen/activity_horizontal_margin"
  android:paddingRight="@dimen/activity_horizontal_margin"
  android:paddingTop="@dimen/activity_vertical_margin"
  tools:context="mao.example.quicksend.MainActivity" >
  <EditText
    android:id="@+id/editTextIP"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="@string/text_IP" />
  <Button
    android:id="@+id/buttonConnect"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/text_connect" />
  <EditText
    android:id="@+id/editTextFilePath"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="@string/text_filePath" >
    <requestFocus />
  </EditText>
  <Button
    android:id="@+id/buttonFileSel"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/text_sel" />
  <Button
    android:id="@+id/buttonSend"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/text_send" />
</LinearLayout>

More readers interested in Android-related content can view the site's topics: Summary of Android Communication, Summary of Android Debugging Skills and Frequently Asked Questions, Introduction to Android Development and Advanced Tutorials, Summary of Android Multimedia Operating Skills (Audio, Video, Recording, etc.), Summary of Usage of Android Basic Components, Summary of Android View View Skills, andAndroid Layout layout Skills Summary and Android Control Usage Summary

I hope that the description in this paper will be helpful to everyone's Android program design.