Java 多线程编程实战：匿名Runnable、继承Thread、自定义异常

题目1：使用匿名Runnable实现线程计算

public class Main {
    public static void main(String[] args) {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                int sum = 0;
                for (int i = 1; i <= 500; i++) {
                    sum += i;
                }
                System.out.println('1--500所有数字的累加和为：' + sum);
            }
        });
        thread.start();
    }
}

题目2：继承Thread类实现定时打印

public class MyThread extends Thread {
    @Override
    public void run() {
        DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        for (int i = 1; i <= 10; i++) {
            System.out.println(dateFormat.format(new Date()));
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class Main {
    public static void main(String[] args) {
        MyThread myThread = new MyThread();
        myThread.start();
    }
}

题目3：使用自定义异常实现用户登陆

public class LoginException extends Exception {
    public LoginException(String message) {
        super(message);
    }
}

public class Main {
    public static void main(String[] args) {
        try {
            login("admin", "123");
        } catch (LoginException e) {
            e.printStackTrace();
        }
    }

    public static void login(String username, String password) throws LoginException {
        if (!"admin".equals(username)) {
            throw new LoginException("用户名不存在");
        }
        if (!"admin".equals(password)) {
            throw new LoginException("密码错误");
        }
        System.out.println("欢迎" + username);
    }
}

以上代码示例展示了在Java中使用匿名Runnable、继承Thread类和自定义异常来实现多线程编程的常见场景，你可以根据实际需要进行修改和扩展。