# Thread中一些簡單的API ```java /** * @program: ThreadDemo * @description: Thread中一些簡單的API * @author: hs96.cn@Gmail.com * @create: 2020-08-28 */ public class ThreadSimpleAPI { public static void main(String[] args) { Thread t1 = new Thread(() -> { Optional.of("Hello").ifPresent(System.out::println); try { Thread.sleep(1_000); } catch (InterruptedException e) { e.printStackTrace(); } }, "t1"); t1.start(); // 線程名稱。 Optional.of(t1.getName()).ifPresent(System.out::println); // 線程ID。++threadSeqNumber Optional.of(t1.getId()).ifPresent(System.out::println); // 線程優先級，默認為5. Optional.of(t1.getPriority()).ifPresent(System.out::println); } } ``` 很簡單的api運行效果如下：  接下來再通過代碼來驗證：*線程不一定會按照指定的優先級執行*。 ```java import java.util.Optional; /** * @program: ThreadDemo * @description: 線程優先級：驗證：線程不一定會按照指定的優先級執行。 * @author: hs96.cn@Gmail.com * @create: 2020-08-28 */ public class ThreadSimpleAPI2 { public static void main(String[] args) { Thread t1 = new Thread(() -> { for (int i = 0; i < 1000; i++) { Optional.of(Thread.currentThread().getName() + "-Index-" + i).ifPresent(System.out::println); } }, "t1"); t1.setPriority(Thread.MAX_PRIORITY); Thread t2 = new Thread(() -> { for (int i = 0; i < 1000; i++) { Optional.of(Thread.currentThread().getName() + "-Index-" + i).ifPresent(System.out::println); } }, "t2"); t2.setPriority(Thread.NORM_PRIORITY); Thread t3 = new Thread(() -> { for (int i = 0; i < 1000; i++) { Optional.of(Thread.currentThread().getName() + "-Index-" + i).ifPresent(System.out::println); } }, "t3"); t3.setPriority(Thread.MIN_PRIORITY); t1.start(); t2.start(); t3.start(); } } ``` 運行結果如下：  可以看到他們是交替執行的，所以線程的優先級我們應該在邏輯上去實現。這里就做個了解。