[Java]簡單的Socket Client Server

這是一個超簡單的Client Server範例，Server部份利用Thread來常駐執行，而Client利用Socket去連接指定的port，送出一個字元組給OutputStream，而Server接收到請求後，使用InputStream來取得資料。

這裡有篇介紹Socket Server的原理Thread應用-Java SocketServer，還有一篇傳送物件Serializable序列化Socket傳送範例，這篇算是比較進階。

程式碼包裝在jar裡，利用二個command視窗，一個執行Server一個執行Client，結果如下：

原始碼及jar下載：

點我下載

主要的Server端程式碼

package test;

import java.net.ServerSocket;
import java.net.Socket;

public class SocketServer extends java.lang.Thread {

    private boolean OutServer = false;
    private ServerSocket server;
    private final int ServerPort = 8765;// 要監控的port

    public SocketServer() {
        try {
            server = new ServerSocket(ServerPort);

        } catch (java.io.IOException e) {
            System.out.println("Socket啟動有問題 !");
            System.out.println("IOException :" + e.toString());
        }
    }

    public void run() {
        Socket socket;
        java.io.BufferedInputStream in;

        System.out.println("伺服器已啟動 !");
        while (!OutServer) {
            socket = null;
            try {
                synchronized (server) {
                    socket = server.accept();
                }
                System.out.println("取得連線 : InetAddress = "
                        + socket.getInetAddress());
                // TimeOut時間
                socket.setSoTimeout(15000);

                in = new java.io.BufferedInputStream(socket.getInputStream());
                byte[] b = new byte[1024];
                String data = "";
                int length;
                while ((length = in.read(b)) > 0)// <=0的話就是結束了
                {
                    data += new String(b, 0, length);
                }

                System.out.println("我取得的值:" + data);
                in.close();
                in = null;
                socket.close();

            } catch (java.io.IOException e) {
                System.out.println("Socket連線有問題 !");
                System.out.println("IOException :" + e.toString());
            }

        }
    }

    public static void main(String args[]) {
        (new SocketServer()).start();
    }

}

Client端程式碼

package test;

import java.net.InetSocketAddress;
import java.net.Socket;
import java.io.BufferedOutputStream;

public class SocketClient {
    private String address = "127.0.0.1";// 連線的ip
    private int port = 8765;// 連線的port

    public SocketClient() {

        Socket client = new Socket();
        InetSocketAddress isa = new InetSocketAddress(this.address, this.port);
        try {
            client.connect(isa, 10000);
            BufferedOutputStream out = new BufferedOutputStream(client
                    .getOutputStream());
            // 送出字串
            out.write("Send From Client ".getBytes());
            out.flush();
            out.close();
            out = null;
            client.close();
            client = null;

        } catch (java.io.IOException e) {
            System.out.println("Socket連線有問題 !");
            System.out.println("IOException :" + e.toString());
        }
    }

    public static void main(String args[]) {
        new SocketClient();
    }
}

啟動Main

package test;

public class Main {

    public static void main(String args[])
    {
        if(args.length==0)
            System.out.println("請傳入參數server或client");
        if(args[0].equals("server"))
            (new SocketServer()).start();
        else
            new SocketClient();
    }
}