Java監控線程池

ThreadPoolExecutor提供了一組方法用于監控線程池。

int getActiveCount() 獲得線程池中當前活動線程的數量。

long getCompletedTaskCount() 返回線程池完成任務的數量。

int getCorePoolSize() 線程池中核心線程的數量。

int getLargestPoolSize() 返回線程池曾經達到的線程的最大數。

int getMaximumPoolSize() 返回線程池的最大容量。

int getPoolSize() 當前線程池的大小。

BlockingQueue getQueue() 返回阻塞隊列。

long getTaskCount() 返回線程池收到的任務總數。

package com.wkcto.threadpool;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * 監控線程池
 */
public class Test05 {
    public static void main(String[] args) throws InterruptedException {
        //先定義任務
        Runnable r = new Runnable() {
            @Override
            public void run() {
                System.out.println(Thread.currentThread().getId() + " 編號 的線程開始執行: " + System.currentTimeMillis());
                try {
                    Thread.sleep(10000);    //線程睡眠20秒,模擬任務執行時長
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        };

        //定義線程池
        ThreadPoolExecutor poolExecutor = new ThreadPoolExecutor(2, 5, 0, TimeUnit.SECONDS, new ArrayBlockingQueue<>(5), Executors.defaultThreadFactory(), new ThreadPoolExecutor.DiscardPolicy());

        //向線程池提交30個任務
        for (int i = 0; i < 30; i++) {
            poolExecutor.submit(r);
            System.out.println("當前線程池核心線程數量: " + poolExecutor.getCorePoolSize() + ", 最大線程數:" + poolExecutor.getMaximumPoolSize() + ",當前線程池大小:" + poolExecutor.getPoolSize() + ",活動線程數量:" + poolExecutor.getActiveCount()+ ",收到任務數量:" + poolExecutor.getTaskCount() + ",完成任務數: " + poolExecutor.getCompletedTaskCount() + ",等待任務數:" + poolExecutor.getQueue().size()) ;
            TimeUnit.MILLISECONDS.sleep(500);
        }

        System.out.println("-----------------------------------------------");
        while ( poolExecutor.getActiveCount() >= 0 ){
            System.out.println("當前線程池核心線程數量: " + poolExecutor.getCorePoolSize() + ", 最大線程數:" + poolExecutor.getMaximumPoolSize() + ",當前線程池大小:" + poolExecutor.getPoolSize() + ",活動線程數量:" + poolExecutor.getActiveCount()+ ",收到任務數量:" + poolExecutor.getTaskCount() + ",完成任務數: " + poolExecutor.getCompletedTaskCount() + ",等待任務數:" + poolExecutor.getQueue().size()) ;
            Thread.sleep(1000);
        }
    }

}