一、线程的ThreadGroup

Thread和ThreadGroup的关系：

二、创建ThreadGroup

package p106_thread_group;

/**
 * @ClassName ThreadGroupCreator
 * @Description TODO
 * 创建ThreadGroup
 * @Author Cays
 * @Date 2019/5/3 21:50
 * @Version 1.0
 **/
public class ThreadGroupCreator {
    public static void main(String[] args) {
        // 1. 获取当前线程的group
        ThreadGroup currentGroup = Thread.currentThread().getThreadGroup();
        // 2. 定义一个ThreadGroup
        ThreadGroup group1 = new ThreadGroup("group1");
        // 3. group1的父ThreadGroup
        System.out.println("group1 parent ThreadGroup:"+group1.getParent());
        // 4. 定义Group2，指定group1为父ThreadGroup
        ThreadGroup group2 = new ThreadGroup(group1,"group2");
        // 5. 输出group2的父ThreadGroup
        System.out.println("group2 parent ThreadGroup:"+group2.getParent());
    }
}

结果：