转自:http://blog.youkuaiyun.com/a352193394/article/details/39323427
当创建了好几个线程的时候,很多线程的工作任务是类似或者一致的,这样我们就可以使用ThreadGroup来管理他
们,ThreadGroup可以随时的获取在他里面的线程的运行状态,信息,或者一条命令关闭掉这个group里面的所有线
程,非常的简单实用,下面我们用一个例子来说明一下如何使用。
import java.util.Date;
import java.util.Random;
import java.util.concurrent.TimeUnit;
public class SearchTask implements Runnable {
public SearchTask(Result result) {
this.result = result;
}
private Result result;
@Override
public void run() {
String name = Thread.currentThread().getName();
System.out.println("Thread Start " + name);
try {
doTask();
result.setName(name);
} catch (InterruptedException e) {
System.out.printf("Thread %s: Interrupted\n", name);
return;
}
System.out.println("Thread end " + name);
}
private void doTask() throws InterruptedException {
Random random = new Random((new Date()).getTime());
int value = (int) (random.nextDouble() * 100);
System.out.printf("Thread %s: %d\n", Thread.currentThread().getName(),
value);
TimeUnit.SECONDS.sleep(value);
}
public static void main(String[] args) {
//创建5个线程,并入group里面进行管理
ThreadGroup threadGroup = new ThreadGroup("Searcher");
Result result = new Result();
SearchTask searchTask = new SearchTask(result);
for (int i = 0; i < 5; i++) {
Thread thred = new Thread(threadGroup, searchTask);
thred.start();
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
//通过这种方法可以看group里面的所有信息
System.out.printf("Number of Threads: %d\n", threadGroup.activeCount());
System.out.printf("Information about the Thread Group\n");
threadGroup.list();
//这样可以复制group里面的thread信息
Thread[] threads = new Thread[threadGroup.activeCount()];
threadGroup.enumerate(threads);
for (int i = 0; i < threadGroup.activeCount(); i++) {
System.out.printf("Thread %s: %s\n", threads[i].getName(),
threads[i].getState());
}
waitFinish(threadGroup);
//将group里面的所有线程都给interpet
threadGroup.interrupt();
}
private static void waitFinish(ThreadGroup threadGroup) {
while (threadGroup.activeCount() > 9) {
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}