线程组
线程组的作用是，可以批量的管理线程或线程组对象，有效地对线程或线程组对象进行组织
线程对象关联线程组：1级关联
package Seven;public class ThreadA extends Thread { @Override public void run() { try { while (!Thread.currentThread().isInterrupted()) { System.out.println("ThreadName=" + Thread.currentThread().getName()); Thread.sleep(3000); } } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } }} package Seven;public class ThreadB extends Thread { @Override public void run() { try { while (!Thread.currentThread().isInterrupted()) { System.out.println("ThreadName=" + Thread.currentThread().getName()); Thread.sleep(3000); } } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } }} package Seven;public class Run { public static void main(String[] args) { ThreadA aRunnable = new ThreadA(); ThreadB bRunnable = new ThreadB(); ThreadGroup group = new ThreadGroup("高洪岩的线程组"); Thread aThread = new Thread(group, aRunnable); Thread bThread = new Thread(group, bRunnable); aThread.start(); bThread.start(); System.out.println("活动的线程数为：" + group.activeCount()); System.out.println("线程组的名称为：" + group.getName()); }} 
线程对象关联线程组：多级关联
package Seven;public class Run { public static void main(String[] args) { // 在main组中添加一个线程组A，然后在这个A组中添加线程对象Z // 方法activeGroupCount()和activeCount()的值不是固定的 // 是系统中环境的一个快照 ThreadGroup mainGroup = Thread.currentThread().getThreadGroup(); ThreadGroup group = new ThreadGroup(mainGroup, "A"); Runnable runnable = new Runnable() { @Override public void run() { try { System.out.println("runMethod!"); Thread.sleep(10000);// 线程必须在运行状态才可以受组管理 } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }; Thread newThread = new Thread(group, runnable); newThread.setName("Z"); newThread.start();// 线程必须启动然后才归到组A中 // /// ThreadGroup[] listGroup = new ThreadGroup[Thread.currentThread() .getThreadGroup().activeGroupCount()]; Thread.currentThread().getThreadGroup().enumerate(listGroup); System.out.println("main线程中有多少个子线程组：" + listGroup.length + " 名字为：" + listGroup[0].getName()); Thread[] listThread = new Thread[listGroup[0].activeCount()]; listGroup[0].enumerate(listThread); System.out.println(listThread[0].getName()); }} 
线程组自动归属特性
自动归属就是自动归到当前线程组中
package Seven;public class Run { public static void main(String[] args) { System.out.println("A处线程："+Thread.currentThread().getName() + " 所属的线程组名为：" + Thread.currentThread().getThreadGroup().getName()+ " " + " 中有线程组数量："+Thread.currentThread().getThreadGroup().activeGroupCount()); ThreadGroup group=new ThreadGroup("新的组"); System.out.println("B处线程："+Thread.currentThread().getName() + " 所属的线程组名为：" + Thread.currentThread().getThreadGroup().getName()+ " " +" 中有线程组数量："+Thread.currentThread().getThreadGroup().activeGroupCount()); ThreadGroup[] threadGroup=new ThreadGroup[Thread.currentThread().getThreadGroup().activeGroupCount()]; Thread.currentThread().getThreadGroup().enumerate(threadGroup); for (int i = 0; i < threadGroup.length; i++) { System.out.println("第一个线程组名称为："+threadGroup[i].getName()); } }}
未完，待续。。。