android socketプログラミング例

Androidクライアントがsocketを介してサーバと通信するには、次のステップに分けられます.
アプリケーションとサーバの通信は、TCP信頼性通信とUDP信頼性通信の2つのモードを採用することができる.
(1)IPアドレスとポートでSocketをインスタンス化し、サーバへの接続を要求する.
     socket = new Socket(HOST, PORT);//host:サーバのIPアドレスport:サーバのポート番号
(2)Socketストリームを取得して読み書きを行い、BufferWriterまたはPrintWriterにストリームをパッケージする.
   PrintWriter out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(socket.getOutputStream())),true);  
ここには3つのクラスがあります.socket.getoOutputStreamはsocketの出力バイトストリームを得,OutputStreamWriterはバイトが文字ストリームに変換される橋渡しであり,BufferWriterは文字ストリームであり,PrintWriterにパッケージされる.
(3)Socketの読み書き
     if (socket.isConnected()) {                     if (!socket.isOutputShutdown()) {                         out.println(msg);                     }                 }
(4)開いているストリームを閉じる
      out.close();
コードを書く過程でsocket入力ストリームの出力ストリームの閉鎖に注意しなければならない.
 
簡単な例を次に示します.
main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:orientation="vertical" 
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent">  
    <TextView 
    	android:id="@+id/TextView" 
    	android:singleLine="false"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content" />  
    <EditText android:hint="content" 
    	android:id="@+id/EditText01"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content">  
    </EditText>  
    <Button 
    	android:text="send" 
    	android:id="@+id/Button02"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content">  
    </Button>  
</LinearLayout> 

次はandroidクライアントのソースコードです.

package com.android.SocketDemo;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class SocketDemo extends Activity implements Runnable {
    private TextView tv_msg = null;
    private EditText ed_msg = null;
    private Button btn_send = null;
//    private Button btn_login = null;
    private static final String HOST = "192.168.1.223";
    private static final int PORT = 9999;
    private Socket socket = null;
    private BufferedReader in = null;
    private PrintWriter out = null;
    private String content = "";

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        tv_msg = (TextView) findViewById(R.id.TextView);
        ed_msg = (EditText) findViewById(R.id.EditText01);
//        btn_login = (Button) findViewById(R.id.Button01);
        btn_send = (Button) findViewById(R.id.Button02);

        try {
            socket = new Socket(HOST, PORT);
            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(
                    socket.getOutputStream())), true);
        } catch (IOException ex) {
            ex.printStackTrace();
            ShowDialog("login exception" + ex.getMessage());
        }
        btn_send.setOnClickListener(new Button.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String msg = ed_msg.getText().toString();
                if (socket.isConnected()) {
                    if (!socket.isOutputShutdown()) {
                        out.println(msg);
                    }
                }
            }
        });
        new Thread(SocketDemo.this).start();
    }

    public void ShowDialog(String msg) {
        new AlertDialog.Builder(this).setTitle("notification").setMessage(msg)
                .setPositiveButton("ok", new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub

                    }
                }).show();
    }

    public void run() {
        try {
            while (true) {
                if (socket.isConnected()) {
                    if (!socket.isInputShutdown()) {
                        if ((content = in.readLine()) != null) {
                            content += "
";
                            mHandler.sendMessage(mHandler.obtainMessage());
                        } else {

                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            tv_msg.setText(tv_msg.getText().toString() + content);
        }
    };
}

次はサーバ側のjavaコードです.

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;


public class Main {
    private static final int PORT = 9999;
    private List<Socket> mList = new ArrayList<Socket>();
    private ServerSocket server = null;
    private ExecutorService mExecutorService = null; //thread pool
    
    public static void main(String[] args) {
        new Main();
    }
    public Main() {
        try {
            server = new ServerSocket(PORT);
            mExecutorService = Executors.newCachedThreadPool();  //create a thread pool
            System.out.print("server start ...");
            Socket client = null;
            while(true) {
                client = server.accept();
                mList.add(client);
                mExecutorService.execute(new Service(client)); //start a new thread to handle the connection
            }
        }catch (Exception e) {
            e.printStackTrace();
        }
    }
    class Service implements Runnable {
            private Socket socket;
            private BufferedReader in = null;
            private String msg = "";
            
            public Service(Socket socket) {
                this.socket = socket;
                try {
                    in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                    msg = "user" +this.socket.getInetAddress() + "come toal:"
                        +mList.size();
                    this.sendmsg();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                
            }

            @Override
            public void run() {
                // TODO Auto-generated method stub
                try {
                    while(true) {
                        if((msg = in.readLine())!= null) {
                            if(msg.equals("exit")) {
                                System.out.println("ssssssss");
                                mList.remove(socket);
                                in.close();
                                msg = "user:" + socket.getInetAddress()
                                    + "exit total:" + mList.size();
                                socket.close();
                                this.sendmsg();
                                break;
                            } else {
                                msg = socket.getInetAddress() + ":" + msg;
                                this.sendmsg();
                            }
                        }
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
          
           public void sendmsg() {
               System.out.println(msg);
               int num =mList.size();
               for (int index = 0; index < num; index ++) {
                   Socket mSocket = mList.get(index);
                   PrintWriter pout = null;
                   try {
                       pout = new PrintWriter(new BufferedWriter(
                               new OutputStreamWriter(mSocket.getOutputStream())),true);
                       pout.println(msg);
                   }catch (IOException e) {
                       e.printStackTrace();
                   }
               }
           }
        }    
}

AndroidManifestでxmlにネットワークへのアクセス権を追加