Java如何检查线程组是否已被销毁？

可以使用 ThreadGroup.isDestroyed ()方法检查线程组及其子组是否已被销毁。

package org.nhooo.example.lang;

public class CheckGroupDestroy {
    public static void main(String[] args) {
        ThreadGroup grandParent = new ThreadGroup("GrandParent");
        ThreadGroup uncle = new ThreadGroup(grandParent, "Uncle");
        ThreadGroup parent = new ThreadGroup(grandParent, "Parent");
        ThreadGroup son = new ThreadGroup(parent, "Son");
        ThreadGroup daughter = new ThreadGroup(parent, "Daughter");
        ThreadGroup neighbour = new ThreadGroup("Neighbour");

        ThreadGroup[] groupArray = {
                grandParent, uncle, parent, son, daughter, neighbour
        };

        // 销毁“父”组及其所有子组
        parent.destroy();

        for (ThreadGroup tg : groupArray) {
            if (tg.isDestroyed()) {
                System.out.println(tg.getName() + " is destroyed");
            } else {
                System.out.println(tg.getName() + " is not destroyed");
            }
        }
    }
}

结果是：

GrandParent is not destroyed
Uncle is not destroyed
Parent is destroyed
Son is destroyed
Daughter is destroyed
Neighbour is not destroyed