public class ThreadStateDemo1 {
    public static void main(String[] args) throws InterruptedException {
        // 1. 創(chuàng)建線程，此時(shí)狀態(tài)為 NEW
        Thread thread = new Thread(() -> {
            System.out.println("線程執(zhí)行中，當(dāng)前狀態(tài)：" + Thread.currentThread().getState());
            // 模擬任務(wù)執(zhí)行
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }, "基礎(chǔ)狀態(tài)線程");
        System.out.println("調(diào)用start()前，線程狀態(tài)：" + thread.getState()); // NEW
        // 2. 啟動(dòng)線程，進(jìn)入 RUNNABLE 狀態(tài)
        thread.start();
        Thread.sleep(50); // 等待線程進(jìn)入執(zhí)行狀態(tài)
        System.out.println("線程執(zhí)行中，主線程觀察到的狀態(tài)：" + thread.getState()); // RUNNABLE
        // 3. 等待線程執(zhí)行完畢
        thread.join();
        System.out.println("線程執(zhí)行完畢，當(dāng)前狀態(tài)：" + thread.getState()); // TERMINATED
    }
}

public class ThreadStateDemo2 {
    // 定義一個(gè)鎖對(duì)象
    private static final Object LOCK = new Object();
    public static void main(String[] args) throws InterruptedException {
        // 線程1：先獲取鎖，持有鎖1秒
        Thread thread1 = new Thread(() -> {
            synchronized (LOCK) {
                try {
                    System.out.println(Thread.currentThread().getName() + " 獲取到鎖，狀態(tài)：RUNNABLE");
                    Thread.sleep(1000); // 持有鎖，讓線程2阻塞
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "線程1");
        // 線程2：后獲取鎖，會(huì)進(jìn)入 BLOCKED 狀態(tài)
        Thread thread2 = new Thread(() -> {
            synchronized (LOCK) {
                System.out.println(Thread.currentThread().getName() + " 成功獲取鎖，狀態(tài)回到 RUNNABLE");
            }
        }, "線程2");
        // 啟動(dòng)線程1和線程2
        thread1.start();
        Thread.sleep(100); // 確保線程1先獲取鎖
        thread2.start();
        // 觀察線程2的狀態(tài)
        Thread.sleep(200);
        System.out.println(thread2.getName() + " 等待鎖，狀態(tài)：" + thread2.getState()); // BLOCKED
        // 等待線程1執(zhí)行完畢，線程2獲取鎖
        thread1.join();
        Thread.sleep(200);
        System.out.println(thread2.getName() + " 執(zhí)行中，狀態(tài)：" + thread2.getState()); // RUNNABLE
    }
}

public class ThreadStateDemo3 {
    private static final Object LOCK = new Object();
    private static Thread waitThread; // 等待線程
    public static void main(String[] args) throws InterruptedException {
        // 等待線程：調(diào)用wait()進(jìn)入WAITING狀態(tài)
        waitThread = new Thread(() -> {
            synchronized (LOCK) {
                try {
                    System.out.println(Thread.currentThread().getName() + " 調(diào)用wait()，進(jìn)入WAITING狀態(tài)");
                    LOCK.wait(); // 無(wú)參wait，釋放鎖
                    System.out.println(Thread.currentThread().getName() + " 被喚醒，狀態(tài)回到RUNNABLE");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "等待線程");
        // 喚醒線程：調(diào)用notify()喚醒等待線程
        Thread notifyThread = new Thread(() -> {
            synchronized (LOCK) {
                System.out.println(Thread.currentThread().getName() + " 獲取鎖，準(zhǔn)備喚醒等待線程");
                LOCK.notify(); // 喚醒等待線程
                try {
                    Thread.sleep(500); // 持有鎖，讓等待線程先處于WAITING→BLOCKED
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }, "喚醒線程");
        waitThread.start();
        Thread.sleep(200);
        System.out.println(waitThread.getName() + " 當(dāng)前狀態(tài)：" + waitThread.getState()); // WAITING
        notifyThread.start();
        notifyThread.join();
        Thread.sleep(200);
        System.out.println(waitThread.getName() + " 最終狀態(tài)：" + waitThread.getState()); // RUNNABLE/TERMINATED
    }
}

public class ThreadStateDemo4 {
    public static void main(String[] args) throws InterruptedException {
        Thread sleepThread = new Thread(() -> {
            try {
                System.out.println(Thread.currentThread().getName() + " 調(diào)用sleep(1000)，進(jìn)入TIMED_WAITING狀態(tài)");
                Thread.sleep(1000); // 超時(shí)等待1秒
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread().getName() + " 超時(shí)喚醒，狀態(tài)回到RUNNABLE");
        }, "睡眠線程");
        sleepThread.start();
        Thread.sleep(200);
        System.out.println(sleepThread.getName() + " 當(dāng)前狀態(tài)：" + sleepThread.getState()); // TIMED_WAITING
        sleepThread.join();
        System.out.println(sleepThread.getName() + " 執(zhí)行完畢，狀態(tài)：" + sleepThread.getState()); // TERMINATED
    }
}

jps
# 輸出示例：1234 ThreadStateDemo2 （1234為PID）

jstack 1234 > thread_dump.txt

"線程2" #13 prio=5 os_prio=31 tid=0x00007f8b1282e000 nid=0x5003 waiting for monitor entry [0x0000700001a6f000]
   java.lang.Thread.State: BLOCKED (on object monitor)
        at ThreadStateDemo2.lambda$main$1(ThreadStateDemo2.java:18)
        - waiting to lock <0x000000076ab81810> (a java.lang.Object)
        - locked <0x000000076ab81810> (a java.lang.Object)