Thread类的enumerate()方法用于将每个活动线程的线程组及其子组复制到指定的数组中。 此方法使用tarray参数调用enumerate方法。
此方法使用activeCount方法来估计数组应该有多大。 如果数组的长度太短而无法容纳所有线程，则会以静默方式忽略额外的线程。
语法
public static int enumerate(Thread[] tarray)
参数
tarray：此方法是要复制到的Thread对象数组。
返回
此方法返回放入数组的线程数。
示例
public class JavaEnumerateExp extends Thread
{
JavaEnumerateExp(String threadname, ThreadGroup tg)
{
super(tg, threadname);
start();
}
public void run()
{
for (int i = 0; i < 5; i++)
{
try
{
Thread.sleep(10);
}
catch (InterruptedException ex) {
System.out.println("Exception encounterted");}
}
System.out.println(Thread.currentThread().getName() +" completed executing");
}
public static void main(String arg[]) throws InterruptedException,SecurityException
{
// creating the ThreadGroup
ThreadGroup g1 = new ThreadGroup("Parent thread");
// creating a child ThreadGroup for parent ThreadGroup
ThreadGroup g2 = new ThreadGroup(g1, "child thread");
// creating a thread
JavaEnumerateExp t1 = new JavaEnumerateExp("Thread-1", g1);
System.out.println("Starting of Thread-1");
// creating another thread
JavaEnumerateExp t2 = new JavaEnumerateExp("Thread-2", g1);
System.out.println("Starting of Thread-2");
// returns the number of threads put into the array
Thread[] group = new Thread[g1.activeCount()];
int count = g1.enumerate(group);
// prints active threads
for (int i = 0; i < count; i++)
{
System.out.println(group[i].getName() + " found");
}
}
}
执行上面示例代码，得到以下结果：
Starting of Thread-1
Starting of Thread-2
Thread-1 found
Thread-2 found
Thread-1 completed executing
Thread-2 completed executing
