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

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:orientation="vertical"  xmlns:tools="http://schemas.android.com/tools"  android:id="@+id/activity_main"  android:layout_width="match_parent"  android:layout_height="match_parent"  tools:context="com.ysp.asus.experiment_02.MainActivity"  android:weightSum="10">  <Button    android:layout_width="match_parent"    android:layout_height="0dp"    android:layout_weight="1"    android:background="#03A9F4"    android:textColor="#FFFFFFFF"    android:textSize="30sp"    android:text="IP"    android:id="@+id/myIP"/>  <!--點擊開始聊天-->  <LinearLayout    android:orientation="horizontal"    android:layout_width="match_parent"    android:layout_height="0dp"    android:layout_weight="1"    android:weightSum="10">    <!--IP-->    <EditText      android:layout_width="match_parent"      android:layout_height="match_parent"      android:layout_weight="1"      android:id="@+id/IP"      android:hint="請寫入對方通訊地址IP"      />  </LinearLayout>  <!--顯示聊天記錄-->  <EditText    android:layout_width="match_parent"    android:layout_height="0dp"    android:layout_weight="7"    android:gravity="top"    android:editable="false"    android:scrollbars="vertical"    android:id="@+id/receiveMessage"/>  <!--用于寫入發送信息和按鈕-->  <LinearLayout    android:layout_width="match_parent"    android:layout_height="0dp"    android:layout_weight="1">    <EditText      android:layout_width="0dp"      android:layout_weight="8"      android:layout_height="match_parent"      android:hint="填寫要發送的信息"      android:id="@+id/message"/>    <Button      android:layout_width="0dp"      android:layout_weight="2"      android:layout_height="match_parent"      android:text="發送消息"      android:background="#03A9F4"      android:textColor="#FFFFFFFF"      android:id="@+id/sendMessage"/>  </LinearLayout></LinearLayout>

package com.ysp.asus.experiment_02;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.net.Socket;import java.net.UnknownHostException;/** * Created by asus on 2017/3/16. */public class ChatClient {  public Socket requestSocket(String host) throws UnknownHostException,IOException{    Socket socket=new Socket(host,5000);    return socket;  }  public void sendMsg(Socket socket,String msg)throws IOException{    BufferedWriter writer=new BufferedWriter(        new OutputStreamWriter(socket.getOutputStream())    );    writer.write(msg.replace("/n","")+"/n");    writer.flush();  }  public String receiveMsg(Socket socket)throws IOException{    BufferedReader reader=new BufferedReader(        new InputStreamReader(socket.getInputStream())    );    String txt=reader.readLine();    return txt;  }}

package com.ysp.asus.experiment_02;import android.os.Handler;import android.os.Message;import android.util.Log;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.net.ServerSocket;import java.net.Socket;/** * Created by asus on 2017/3/16. */public class ChatServer extends Thread {  public  ChatServer() throws IOException {      createSocket();  }  public void run(){    Socket client;    String txt;    Log.i("信息","成功開始服務器，端口為："+PORT);    try{      while (true){        client=ResponseSocket();        while(true){          txt=ReceiveMsg(client);          System.out.println(txt);          Message message1 = new Message();          message1.obj =txt+"/n";          com.ysp.asus.experiment_02.MainActivity.handler.sendMessage(message1);          if(true)            break;        }//        CloseSocket(client);      }    }catch (IOException e){    }  }  private Handler mHandler = new Handler(){    public void handleMessage(Message msg) {    };  };  public ServerSocket server=null;  private  int PORT =5000;  private BufferedWriter writer;  private BufferedReader reader;  public void createSocket() throws IOException{    server=new ServerSocket(PORT,100);  }  public Socket ResponseSocket() throws IOException{    Socket client =server.accept();    return client;  }  public void CloseSocket(Socket socket) throws IOException{    reader.close();    socket.close();    server.close();  }  public void sendMsg(Socket socket,String string)throws IOException{    writer=new BufferedWriter(        new OutputStreamWriter(socket.getOutputStream())    );    writer.write("msg"+string);    writer.flush();  }  public String ReceiveMsg(Socket socket) throws IOException{    reader=new BufferedReader(        new InputStreamReader(socket.getInputStream())    );        String txt ="對方:"+reader.readLine();    return txt;  }}

package com.ysp.asus.experiment_02;import android.content.Context;import android.net.wifi.WifiInfo;import android.net.wifi.WifiManager;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.text.ClipboardManager;import android.util.Log;import android.view.View;import android.view.inputmethod.InputMethodManager;import android.widget.Button;import android.widget.EditText;import java.io.IOException;import java.net.Socket;import static com.ysp.asus.experiment_02.R.id.receiveMessage;public class MainActivity extends AppCompatActivity {  final ChatServer chatServer=null;  static String text="";  static EditText receivemessage=null;  final ChatClient chatClient = new ChatClient();  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);//    定義相關的變量     receivemessage=(EditText) findViewById(receiveMessage);    final EditText message=(EditText)findViewById(R.id.message);    final EditText IP = (EditText)findViewById(R.id.IP);    final Button sendmessage = (Button)findViewById(R.id.sendMessage);    final Button myIP =(Button) findViewById(R.id.myIP);//    獲取wifi下的IP地址并顯示    //獲取wifi服務    WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);    //判斷wifi是否開啟    if (!wifiManager.isWifiEnabled()) {      wifiManager.setWifiEnabled(true);    }    WifiInfo wifiInfo = wifiManager.getConnectionInfo();    int ipAddress = wifiInfo.getIpAddress();    String ip = intToIp(ipAddress);    myIP.setText(ip);//   點擊實現復制內容到粘貼板    myIP.setClickable(true);    myIP.setOnClickListener(new Button.OnClickListener() {      public void onClick(View arg0) {        ClipboardManager cm = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);        // 將文本內容放到系統剪貼板里。        cm.setText(myIP.getText().toString());      }    });//    初始化看是服務器    try{      ChatServer chatServer=new ChatServer();      chatServer.start();    }catch(IOException e){      Log.e("錯誤","開啟服務器失敗");      e.printStackTrace();    }//    點擊按鈕發送數據給相應的IP地址    sendmessage.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        HideKeyboard(sendmessage);        new Thread(new Runnable() {          @Override          public void run() {            try {              Socket socket=chatClient.requestSocket(IP.getText().toString());              chatClient.sendMsg(socket,message.getText().toString());              Message message1 = new Message();              message1.obj ="自己： "+message.getText().toString()+"/n";              handler.sendMessage(message1);            }catch (IOException e){              Log.e("錯誤","發送失敗");            }          }        }).start();      }    });  }  public static Handler handler=new Handler(){    @Override    public void handleMessage(Message msg) {      super.handleMessage(msg);      Log.i("信息","其他線程發過來："+msg);      text+=msg.obj.toString();      receivemessage.setText(text);      receivemessage.setSelection(receivemessage.getText().length(), receivemessage.getText().length());    }  };//  用于將結果以IP的形式放出  private String intToIp(int i) {    return (i & 0xFF ) + "." +        ((i >> 8 ) & 0xFF) + "." +        ((i >> 16 ) & 0xFF) + "." +        ( i >> 24 & 0xFF) ;  }  //隱藏虛擬鍵盤  public static void HideKeyboard(View v)  {    InputMethodManager imm = ( InputMethodManager ) v.getContext( ).getSystemService( Context.INPUT_METHOD_SERVICE );    if ( imm.isActive( ) ) {      imm.hideSoftInputFromWindow( v.getApplicationWindowToken( ) , 0 );    }  }}