JAVA實現TCPServer和TCPClient

TCPServer

原理：創建服務器套接字，綁定到指定的端口，等待客戶端連接。接受客戶端連接，創建線程處理連接。

代碼實現：

public class TCPServer {

    private int port;
    private boolean isFinished;
    private ServerSocket serverSocket;
    private ArrayList<SocketThread> socketThreads;


    public TCPServer(int port) {
        this.port = port;
        socketThreads = new ArrayList<>();
    }


    public void start() {
        isFinished = false;
        try {
            //創建服務器套接字，綁定到指定的端口
            serverSocket = new ServerSocket(port);
            //等待客戶端連接
            while (!isFinished) {
                Socket socket = serverSocket.accept();//接受連接
                //創建線程處理連接
                SocketThread socketThread = new SocketThread(socket);
                socketThreads.add(socketThread);
                socketThread.start();
            }
        } catch (IOException e) {
            isFinished = true;
        }
    }


    public void stop() {
        isFinished = true;
        for (SocketThread socketThread : socketThreads) {
            socketThread.interrupt();
            socketThread.close();
        }
        try {
            if (serverSocket != null) {
                serverSocket.close();
                serverSocket = null;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private class SocketThread extends Thread {

        private Socket socket;
        private InputStream in;
        private OutputStream out;

        SocketThread(Socket socket) {
            this.socket = socket;
            try {
                in = socket.getInputStream();
                out = socket.getOutputStream();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void run() {
            while (!isInterrupted()) {
                if (in == null) {
                    return;
                }
                try {
                    int available = in.available();
                    if (available > 0) {
                        byte[] buffer = new byte[available];
                        int size = in.read(buffer);
                        if (size > 0) {
                            String data = new String(buffer,0,size);
                            System.out.println("TCPClient say :" + data);
                            //返回結果給TcpClient
                            String response = "TCPServer response:" + data;
                            out.write(response.getBytes());
                            out.flush();
                        }
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        void close() {

            try {
                if (in != null) {
                    in.close();
                }

                if (out != null) {
                    out.close();
                }

                if (socket != null) {
                    socket.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

調用例子：

        //TCPServer開啓
        tcpServer = new TCPServer(port);
        new Thread(()-> tcpServer.start()).start();

        //TCPServer停止
        tcpServer.stop();

TCPClient

原理：創建一個連接的套接字，將此套接字連接到指定IP和端口的服務器，雙方成功建立連接之後，就可以進行數據交互了。
代碼實現：

public abstract class TCPClient {

    private String ip;
    private int port;

    private Socket mSocket;
    private SocketAddress mSocketAddress;
    private OutputStream mOutputStream;
    private InputStream mInputStream;
    private ReadThread mReadThread;
    private boolean _isConnected = false;


    public TCPClient(String ip, int port) {
        this.ip = ip;
        this.port = port;
    }


    public void connect() {

        try {
            this.mSocket = new Socket();
            this.mSocket.setKeepAlive(true);
            this.mSocketAddress = new InetSocketAddress(ip, port);
            this.mSocket.connect( mSocketAddress, 3000);// 設置連接超時時間爲3秒

            this.mOutputStream = mSocket.getOutputStream();
            this.mInputStream = mSocket.getInputStream();

            this.mReadThread = new TCPClient.ReadThread();
            this.mReadThread.start();
            this._isConnected = true;
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void close() {

        if (this.mReadThread != null) {
            this.mReadThread.interrupt();
        }
        if (this.mSocket != null) {
            try {
                this.mSocket.close();
                this.mSocket = null;
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        this._isConnected = false;
    }

    public boolean isConnected() {
        return this._isConnected;
    }


    public void send(byte[] bOutArray) {
        try {
            this.mOutputStream.write(bOutArray);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    protected abstract void onDataReceive(byte[] bytes, int size);

    private class ReadThread extends Thread {
        @Override
        public void run() {
            super.run();
            while (!isInterrupted()) {
                try {
                    if (TCPClient.this.mInputStream == null) {
                        return;
                    }
                    int available = TCPClient.this.mInputStream.available();
                    if (available > 0) {
                        byte[] buffer = new byte[available];
                        int size = TCPClient.this.mInputStream.read(buffer);
                        if (size > 0) {
                            onDataReceive(buffer, size);
                        }
                    } else {
                        Thread.sleep(50);
                    }


                } catch (Throwable e) {
                    System.out.println(e.getMessage());
                    return;
                }
            }
        }
    }
}

調用例子：

       tcpClient = new TCPClient(ip, port) {
            @Override
            protected void onDataReceive(byte[] bytes, int size) {
                String content = "TCPServer say :" + new String(bytes, 0, size);
                System.out.println(content);
            }
        };
        tcpClient.connect();//連接TCPServer
        if (tcpClient.isConnected()) {
            //發送數據
            String outContent = "TCPClient say hello";
            tcpClient.send(outContent.getBytes());
        }


        //關閉連接
        tcpClient.close();