下面是多线程的;每次服务端接受请求，会创建一个线程专门处理这个请求；

虽然是多线程的，但还是阻塞，相当于单线程处理模式

public class TimeServer {

    public static void main(String[] args) {

        int port = 8088;//端口号

        ServerSocket server = null;

        try {

            server = new ServerSocket(port);

            System.out.println("The time server is start in port:"+port);

            Socket socket = null;

            while(true){

                //监听客户端，客户端向服务端发送请求，接收

                socket = server.accept();

                //当监听到客户端请求，服务端会启动一个线程，处理客户端相关业务；服务器端实现多线程

                new Thread(new TimeServerHandler(socket)).start();

            }

        } catch (IOException e) {

            e.printStackTrace();

        }finally{

            if(server != null){

                System.out.println("the server close");

                try {

                    server.close();

                } catch (IOException e) {

                    e.printStackTrace();

                }

                server = null;

            }

        }

    }

}

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服务器处理类；new TimeServerHandler(socket)将socket传入进去，然后生成输入、输出流出处理

public class TimeServerHandler implements Runnable{

    private Socket socket;

    public TimeServerHandler(Socket socket){

        this.socket = socket;

    }

    @Override

    public void run() {

        BufferedReader in = null;

        PrintWriter out = null;

        try {

            in = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));

            out = new PrintWriter(this.socket.getOutputStream());

            String currentTime = null;

            String body = null;

            while(true){

                //读取客户端信息

                body = in.readLine();

                if(body == null)

                    break;

                System.out.println("the time server receive order:"+body);

                currentTime = "QUERY TIME ORDER".equalsIgnoreCase(body) ?

                        new java.util.Date(System.currentTimeMillis()).toString() : "BAD ORDER";

                out.println(currentTime);

            }

        } catch (Exception e) {

            if(in != null){

                try {

                    in.close();

                } catch (IOException e1) {

                    e1.printStackTrace();

                }

            }

            if(out != null){

                out.close();

            }

            if(socket != null){

                try {

                    socket.close();

                } catch (IOException e1) {

                    e1.printStackTrace();

                }

                this.socket = null;

            }

        }

    }

}

------

客户端

public class TimeClient {

    public static void main(String[] args) {

        int port = 8088;//端口

        BufferedReader in = null;

        PrintWriter out = null;

        Socket socket = null;

        try {

            //根据ip地址和端口连接服务器；

            socket = new Socket("127.0.0.1", 8088);

            //使用IO流读取或写入信息

            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

            out = new PrintWriter(socket.getOutputStream());

            out.println("QUERY TIME ORDER");

            System.out.println("send order 2 server succeed");

            String resp = in.readLine();

            System.out.println("NOW IS:"+resp);

        } catch (UnknownHostException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }finally{

            if(out != null){

                out.close();

            }

            if(in != null){

                try {

                    in.close();

                } catch (IOException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

            }

            if(socket != null){

                try {

                    socket.close();

                } catch (IOException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

                socket = null;

            }

        }

    }

}