Java獲取當前進程的所有線程

public class MainClass {

    public static void main(String[] args) {
        ThreadGroup group = Thread.currentThread().getThreadGroup();
        ThreadGroup topGroup = group;
        // 遍歷線程組樹，獲取根線程組
        while (group != null) {
            topGroup = group;
            group = group.getParent();
        }
        // 激活的線程數再加一倍，防止枚舉時有可能剛好有動態線程生成
        int slackSize = topGroup.activeCount() * 2;
        Thread[] slackThreads = new Thread[slackSize];
        // 獲取根線程組下的所有線程，返回的actualSize便是最終的線程數
        int actualSize = topGroup.enumerate(slackThreads);
        Thread[] atualThreads = new Thread[actualSize];
        // 復制slackThreads中有效的值到atualThreads
        System.arraycopy(slackThreads, 0, atualThreads, 0, actualSize);
        System.out.println("Threads size is " + atualThreads.length);
        for (Thread thread : atualThreads) {
            System.out.println("Thread name : " + thread.getName());
        }

    }

}