.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. 分别运用Runnable和Callable接口实现线程：

Runnable接口是Java中定义线程的标准方式，它只有一个run()方法，线程执行的代码就在这个方法里。Callable接口也是Java中定义线程的一种方式，它也只有一个call()方法，与run()方法不同的是，call()方法可以返回一个结果。

使用Runnable接口实现线程：

public class MyRunnable implements Runnable {
    public void run() {
        // 线程执行的代码
    }
}

// 创建线程并启动
MyRunnable myRunnable = new MyRunnable();
Thread thread = new Thread(myRunnable);
thread.start();

使用Callable接口实现线程：

public class MyCallable implements Callable<Integer> {
    public Integer call() throws Exception {
        // 线程执行的代码
        return 123;
    }
}

// 创建线程并启动
MyCallable myCallable = new MyCallable();
FutureTask<Integer> futureTask = new FutureTask<>(myCallable);
Thread thread = new Thread(futureTask);
thread.start();

// 获取线程执行结果
int result = futureTask.get();

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：

同步代码段：

public class MyRunnable implements Runnable {
    private int count = 0;
    private Object lock = new Object();

    public void run() {
        synchronized (lock) {
            for (int i = 0; i < 10000; i++) {
                count++;
            }
        }
    }
}

同步方法：

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

    public synchronized void run() {
        for (int i = 0; i < 10000; i++) {
            count++;
        }
    }
}

同步锁：

public class MyRunnable implements Runnable {
    private int count = 0;
    private Lock lock = new ReentrantLock();

    public void run() {
        lock.lock();
        try {
            for (int i = 0; i < 10000; i++) {
                count++;
            }
        } finally {
            lock.unlock();
        }
    }
}

3. 实验UDP协议实现用户信息的发送和接受功能：

UDP是一种无连接的传输协议，它不需要建立连接就可以发送数据包。UDP协议使用的是面向无连接的通信模式，它不保证数据传输的可靠性。在Java中，使用DatagramSocket和DatagramPacket类来实现UDP协议的数据发送和接收。

发送端代码：

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

接收端代码：

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是一种可靠的面向连接的传输协议，它使用三次握手建立连接，保证数据的可靠传输。在Java中，使用Socket和ServerSocket类来实现TCP协议的数据传输。

客户端代码：

public class TCPClient {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket("127.0.0.1", 8888);
        OutputStream outputStream = socket.getOutputStream();
        FileInputStream fileInputStream = new FileInputStream("test.txt");
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = fileInputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, len);
        }
        fileInputStream.close();
        socket.shutdownOutput();
        InputStream inputStream = socket.getInputStream();
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        while ((len = inputStream.read(buffer)) != -1) {
            byteArrayOutputStream.write(buffer, 0, len);
        }
        String result = new String(byteArrayOutputStream.toByteArray());
        System.out.println(result);
        byteArrayOutputStream.close();
        inputStream.close();
        outputStream.close();
        socket.close();
    }
}

服务端代码：

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("test_copy.txt");
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = inputStream.read(buffer)) != -1) {
            fileOutputStream.write(buffer, 0, len);
        }
        fileOutputStream.close();
        OutputStream outputStream = socket.getOutputStream();
        outputStream.write("Upload success".getBytes());
        outputStream.close();
        inputStream.close();
        socket.close();
        serverSocket.close();
    }
}