用java实现t1，t2,t3三个线程保证t1在获得t2，t3的结果后继续执行

在Java中，为了实现这样的线程同步，可以使用`synchronized`, `wait()`, 和 `notifyAll()` 等并发工具。我们可以创建一个包含共享资源的对象，并利用 `volatile` 关键字防止数据竞争。下面是一个简单的例子：

public class ThreadTask {
    private volatile int result;
    private final Object lock = new Object();
    
    public void startThreads(int t2Result, int t3Result) {
        Thread t1 = new Thread(() -> {
            synchronized (lock) {
                try {
                    result = Math.max(t2Result, t3Result);
                    System.out.println("T1 got results, result is " + result);
                    // Notify T2 and T3 that result is available
                    lock.notifyAll();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });
        
        Thread t2 = new Thread(() -> {
            while (!Thread.currentThread().equals(t1)) {
                try {
                    lock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            // Simulate a task with random delay for result
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            result = t2Result; // Set your own result
        });

        Thread t3 = new Thread(() -> {
            while (!Thread.currentThread().equals(t1)) {
                try {
                    lock.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            // Similar to T2, simulate a task
            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            result = t3Result;
        });

        t1.start();
        t2.start();
        t3.start();

        // Wait for all threads to finish
        try {
            t1.join();
            t2.join();
            t3.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        ThreadTask task = new ThreadTask();
        task.startThreads(10, 20); // Replace with actual values or generate them dynamically
    }
}

在这个例子中，`startThreads`方法启动了三个线程`t1`, `t2`, 和 `t3`。`t1`负责获取并存储结果，然后唤醒等待的`t2`和`t3`。`t2`和`t3`分别模拟延迟任务并在得到通知后设置自己的结果。主线程会等待所有线程完成。