ThreadGroup的简单使用

小咪咪 2022-11-11 14:50 64阅读 0赞

## 1：简答说明 ##

ThreadGroup是用来管理一组线程的，可以控制线程的执行，查看线程的执行状态等操作，方便对于一组线程的统一管理。

## 2：构造函数 ##

### 2.1：Thread构造函数 ###

在创建Thread时可以指定Thread所属的ThreadGroup，其中相关的构造函数如下：

public Thread(ThreadGroup group, Runnable target) { 
        init(group, target, "Thread-" + nextThreadNum(), 0);
    }
    public Thread(ThreadGroup group, Runnable target, String name) { 
        init(group, target, name, 0);
    }
    public Thread(ThreadGroup group, Runnable target, String name,
                      long stackSize) { 
        init(group, target, name, stackSize);
    }
    public Thread(ThreadGroup group, String name) { 
        init(group, null, name, 0);
    }

### 2.2：ThreadGroup构造函数 ###

public ThreadGroup(String name) { 
        this(Thread.currentThread().getThreadGroup(), name);
    }
    public ThreadGroup(ThreadGroup parent, String name) { 
        this(checkParentAccess(parent), parent, name);
    }
    private ThreadGroup(Void unused, ThreadGroup parent, String name) { 
        this.name = name;
        this.maxPriority = parent.maxPriority;
        this.daemon = parent.daemon;
        this.vmAllowSuspension = parent.vmAllowSuspension;
        this.parent = parent;
        parent.add(this);
    }

## 3：例子 ##

public class MyThreadGroupTest { 
        public static void main(String[] args) { 
            ThreadGroup myThreadGroup = new ThreadGroup("dongshidadddy线程组");
            for (int i = 0; i < 5; i++) { 
                new Thread(myThreadGroup, Go::doGo, i + "号线程").start();
            }
            System.out.println("活跃线程数：" + myThreadGroup.activeCount());
            System.out.println("线程组信息：");
            myThreadGroup.list();
        }
    }
    
    class Go { 
        public static void doGo() { 
            try { 
                Thread.sleep(5000);
            } catch (InterruptedException e) { 
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread().getName() + " run");
        }
    }

运行：

活跃线程数：5
    线程组信息：
    java.lang.ThreadGroup[name=dongshidadddy线程组,maxpri=10]
        Thread[0号线程,5,dongshidadddy线程组]
        Thread[1号线程,5,dongshidadddy线程组]
        Thread[2号线程,5,dongshidadddy线程组]
        Thread[3号线程,5,dongshidadddy线程组]
        Thread[4号线程,5,dongshidadddy线程组]
    2号线程 run
    1号线程 run
    3号线程 run
    0号线程 run
    4号线程 run