问题描述
- 关于Android利用局域网进行UDP通信的问题
- 我写了一个小程序准备利用UDP和电脑之间进行通信，然后基于这个做一点东西，可是问题是我用AVD测试很好用的，但是用真机测试就是不行。
我的思路是让电脑和Android设备连接一台路由器，路由器为两台设备分配固定的ip地址进行通信。
拜托大家帮我看看啊，我这才是第一步就郁闷的要死
下面是代码。
1：MainActivitypackage com.company.zebork.testudpll;
import android.app.Activity;
import android.content.Context;
import android.net.wifi.WifiManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;public class MainActivity extends Activity {
EditText text;Button send;Handler handler;Message msg;EditText ad;String address;@Overrideprotected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); text = (EditText) findViewById(R.id.editText); send = (Button) findViewById(R.id.send); ad = (EditText) findViewById(R.id.editText2); handler = new Handler() { @Override public void handleMessage(Message msg) { text.setText(""""); } };/* send.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
handler.handleMessage(msg);
}
});*/send.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { System.out.println(ad.getText().toString()); AsyncTask<String String Void> toSend = new AsyncTask<String String Void>() { @Override protected Void doInBackground(String... params) { address = ad.getText().toString(); UDPClient client = new UDPClient(address); System.out.println(""here"" + address); client.send(text.getText().toString()); msg = new Message(); handler.sendMessage(msg); return null; } @Override protected void onPostExecute(Void aVoid) { super.onPostExecute(aVoid); } }.execute(address); } });}@Overridepublic boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main menu); return true;}@Overridepublic 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(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item);}}
2、UDPClient
package com.company.zebork.testudpll;
import java.io.IOException;
import java.net.*;
public class UDPClient {private DatagramPacket dp;private DatagramSocket ds;private byte[] buf;private String address;public UDPClient(String address) { buf = new byte[4096]; this.address = address; System.out.println(""??"" + address); try { ds = new DatagramSocket(8888); } catch (SocketException e) { e.printStackTrace(); }}public void send(String str) { buf = str.getBytes(); try { dp = new DatagramPacket(buf buf.lengthnew InetSocketAddress(address5679)); ds.send(dp); ds.close(); } catch (UnknownHostException e) { e.printStackTrace(); } catch (SocketException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); }}}
3、AndroidManifest【有些权限我都没有用到，因为调试这个错误才加上的】
<?xml version=""1.0"" encoding=""utf-8""?>
package=""com.company.zebork.testudpll"" ><application android:allowBackup=""true"" android:icon=""@drawable/ic_launcher"" android:label=""@string/app_name"" android:theme=""@style/AppTheme"" > <activity android:name="".MainActivity"" android:label=""@string/app_name"" > <intent-filter> <action android:name=""android.intent.action.MAIN"" /> <category android:name=""android.intent.category.LAUNCHER"" /> </intent-filter> </activity></application>4、activity_main.xml
xmlns:tools=""http://schemas.android.com/tools"" android:layout_width=""match_parent""
android:layout_height=""match_parent"" android:paddingLeft=""@dimen/activity_horizontal_margin""
android:paddingRight=""@dimen/activity_horizontal_margin""
android:paddingTop=""@dimen/activity_vertical_margin""
android:paddingBottom=""@dimen/activity_vertical_margin"" tools:context="".MainActivity""
android:orientation=""vertical""><EditText android:layout_width=""match_parent"" android:layout_height=""wrap_content"" android:id=""@+id/editText"" android:layout_alignParentTop=""true"" android:layout_centerHorizontal=""true"" /><EditText android:layout_width=""match_parent"" android:layout_height=""wrap_content"" android:id=""@+id/editText2"" android:layout_gravity=""center_horizontal"" android:text=""ip"" /><Button android:layout_width=""wrap_content"" android:layout_height=""wrap_content"" android:text=""发送"" android:id=""@+id/send"" android:layout_centerVertical=""true"" android:layout_centerHorizontal=""true"" android:layout_gravity=""center_horizontal"" />5、服务器的Java文件，我是用JavaSE写的，因为不会javaEE
import java.io.IOException;
import java.net.*;
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;public class TestUDPClient extends Frame{
private static DatagramPacket dp;private static DatagramSocket ds;private static TextField text;private static TextArea ta;public static void main(String[] args) { Frame f = new TestUDPClient(); f.setLocation(200 200); f.setSize(300200); f.setVisible(true); text = new TextField(); ta = new TextArea(); f.add(textBorderLayout.SOUTH); f.add(taBorderLayout.CENTER); f.addWindowListener(new WindowAdapter() { @Override public void windowClosing(WindowEvent e) { if(ds!=null) ds.close(); System.exit(0); } }); startServer();}public static void startServer() { byte[] buf = new byte[4096]; dp = new DatagramPacket(bufbuf.length); try { ds = new DatagramSocket(5679); } catch (SocketException e) { e.printStackTrace(); } while(true) { try { ds.receive(dp); if(ta.getText().length() > 0) ta.setText(ta.getText() + ""n"" + new String(buf0dp.getLength())); else ta.setText(new String(buf0dp.getLength())); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } }}}
解决方案
先看是否分配到合法IP，然后就是建立连接是否成功