Java 多線程創建方式二：實現 Runnable 接口、Thread 構造器傳入與啟動

Runnable 接口創建線程兩步走

1. 實現 Runnable 接口，重寫 run()
2. 創建 Thread 實例，構造器傳入 Runnable 實例
3. 調用 Thread.start() 啟動線程

代碼示例

public class MyRunnable implements Runnable {
    public void run() {
        System.out.println(Thread.currentThread().getName());
    }
    public static void main(String[] args) {
        MyRunnable t1 = new MyRunnable();
        MyRunnable t2 = new MyRunnable();
        Thread thread1 = new Thread(t1, "MyThread1");
        Thread thread2 = new Thread(t2);
        thread2.setName("MyThread2");
        thread1.start();
        thread2.start();
    }
}

運行結果

MyThread1
MyThread2

核心要點

• Thread 實現了 Runnable，所以 Thread 子類實例也可作為 target
• 線程名可通過構造器或 setName() 設置
• 必須調用 start() 而非直接調用 run() (後者為主線程同步執行)