1.分别运用Runnable和Callable接口实现线程 2.分别运用同步代码段、同步方法和同步锁的方法实现线程同步 3.实验UDP协议实现用户信息的发送和接受功能 4.运用TCP协议实现向服务器上传文件

1. 运用Runnable和Callable接口实现线程

Runnable接口和Callable接口都可以用来实现线程，但是Callable接口可以返回执行结果，而Runnable接口不能。下面分别给出两种方式的示例代码：

（1）使用Runnable接口实现线程

public class MyRunnable implements Runnable {
    @Override
    public void run() {
        // 线程执行的代码
        System.out.println("线程开始执行");
    }
}

// 在主函数中创建线程并启动
public static void main(String[] args) {
    Thread thread = new Thread(new MyRunnable());
    thread.start();
}

（2）使用Callable接口实现线程

public class MyCallable implements Callable<String> {
    @Override
    public String call() throws Exception {
        // 线程执行的代码
        return "线程执行完毕";
    }
}

// 在主函数中创建线程并启动
public static void main(String[] args) throws ExecutionException, InterruptedException {
    ExecutorService executorService = Executors.newSingleThreadExecutor();
    Future<String> future = executorService.submit(new MyCallable());
    String result = future.get();
    System.out.println(result);
    executorService.shutdown();
}

2. 分别运用同步代码段、同步方法和同步锁的方法实现线程同步

Java中的线程同步可以通过synchronized关键字来实现，有三种方式：同步代码段、同步方法和同步锁。下面分别介绍这三种方式的实现方法。

（1）同步代码段

public class MyRunnable implements Runnable {
    private int count = 0;

    @Override
    public void run() {
        synchronized (this) { // 使用this作为锁对象
            for (int i = 0; i < 5; i++) {
                count++; // 非原子操作
                System.out.println(Thread.currentThread().getName() + " count=" + count);
            }
        }
    }
}

（2）同步方法

public class MyRunnable implements Runnable {
    private int count = 0;

    @Override
    public synchronized void run() { // 使用synchronized修饰方法
        for (int i = 0; i < 5; i++) {
            count++; // 非原子操作
            System.out.println(Thread.currentThread().getName() + " count=" + count);
        }
    }
}

（3）同步锁

public class MyRunnable implements Runnable {
    private int count = 0;
    private final Object lock = new Object(); // 定义一个锁对象

    @Override
    public void run() {
        synchronized (lock) { // 使用lock作为锁对象
            for (int i = 0; i < 5; i++) {
                count++; // 非原子操作
                System.out.println(Thread.currentThread().getName() + " count=" + count);
            }
        }
    }
}

3. 实验UDP协议实现用户信息的发送和接受功能

UDP协议是一种无连接的协议，它不保证数据传输的可靠性、顺序性和唯一性。下面给出发送和接收用户信息的示例代码：

（1）发送用户信息

public class UDPSender {
    public static void main(String[] args) throws IOException {
        DatagramSocket socket = new DatagramSocket();
        String message = "Hello, World!";
        byte[] data = message.getBytes();
        InetAddress address = InetAddress.getByName("127.0.0.1");
        int port = 8888;
        DatagramPacket packet = new DatagramPacket(data, data.length, address, port);
        socket.send(packet);
        socket.close();
    }
}

（2）接收用户信息

public class UDPReceiver {
    public static void main(String[] args) throws IOException {
        DatagramSocket socket = new DatagramSocket(8888);
        byte[] buffer = new byte[1024];
        DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
        socket.receive(packet);
        String message = new String(packet.getData(), 0, packet.getLength());
        System.out.println("Received message: " + message);
        socket.close();
    }
}

4. 运用TCP协议实现向服务器上传文件

TCP协议是一种面向连接的协议，它保证数据传输的可靠性、顺序性和唯一性。下面给出向服务器上传文件的示例代码：

public class TCPClient {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket("localhost", 8888);
        OutputStream outputStream = socket.getOutputStream();
        FileInputStream fileInputStream = new FileInputStream("D:\\test.txt");
        byte[] buffer = new byte[1024];
        int len;
        while ((len = fileInputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, len);
        }
        fileInputStream.close();
        outputStream.close();
        socket.close();
    }
}

public class TCPServer {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = new ServerSocket(8888);
        Socket socket = serverSocket.accept();
        InputStream inputStream = socket.getInputStream();
        FileOutputStream fileOutputStream = new FileOutputStream("D:\\test_copy.txt");
        byte[] buffer = new byte[1024];
        int len;
        while ((len = inputStream.read(buffer)) != -1) {
            fileOutputStream.write(buffer, 0, len);
        }
        fileOutputStream.close();
        inputStream.close();
        socket.close();
        serverSocket.close();
    }
}