boolean isDestroyed()
描述 (Description)
java.lang.ThreadGroup.isDestroyed()方法测试此线程组是否已被销毁。
声明 (Declaration)
以下是java.lang.ThreadGroup.isDestroyed()方法的声明
public boolean isDestroyed()
参数 (Parameters)
NA
返回值 (Return Value)
如果销毁此对象，则此方法返回true。
异常 (Exception)
NA
例子 (Example)
以下示例显示了java.lang.ThreadGroup.isDestroyed（）方法的用法。
package com.iowiki;
import java.lang.*;
public class ThreadGroupDemo implements Runnable {
public static void main(String[] args) {
ThreadGroupDemo tg = new ThreadGroupDemo();
tg.func();
}
public void func() {
try {
// create a parent ThreadGroup
ThreadGroup pGroup = new ThreadGroup("Parent ThreadGroup");
// create a child ThreadGroup for parent ThreadGroup
ThreadGroup cGroup = new ThreadGroup(pGroup, "Child ThreadGroup");
// create a thread
Thread t1 = new Thread(pGroup, this);
System.out.println("Starting " + t1.getName() + "...");
t1.start();
// create another thread
Thread t2 = new Thread(cGroup, this);
System.out.println("Starting " + t2.getName() + "...");
t2.start();
// block until the other threads finish
t1.join();
t2.join();
try {
// child group destroyed
if (!cGroup.isDestroyed()) {
cGroup.destroy();
} else {
System.out.println(cGroup.getName() + " destroyed");
}
} catch(IllegalThreadStateException ex) {
System.out.println(cGroup.getName() + " is empty: " + ex.toString());
}
try {
// parent group destroyed
if (!pGroup.isDestroyed()) {
pGroup.destroy();
} else {
System.out.println(pGroup.getName() + " destroyed");
}
} catch(IllegalThreadStateException ex) {
System.out.println(pGroup.getName() + " is empty: " + ex.toString());
}
} catch (InterruptedException ex) {
System.out.println(ex.toString());
}
}
// implements run()
public void run() {
for(int i = 0;i < 1000;i++) {
i++;
}
System.out.println(Thread.currentThread().getName() + " finished executing.");
}
}
让我们编译并运行上面的程序，这将产生以下结果 -
Starting Thread-0...
Starting Thread-1...
Thread-0 finished executing.
Thread-1 finished executing.
