Java 简单理解 多线程 线程池

如果无法理解，请多读几遍，并自己手动编译几次。

package com.hotpot.main;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class main {
    public static void main (String[] args) {
        //先建立strlist模拟大量数据
        List<String> strlist = new ArrayList<String>();
        for (int i = 0; i < 20; i++) {
            strlist.add("Str" + i);
        }
        //设置线程池维护线程的最大线程数
        int thread = strlist.size() < 5 ? strlist.size() : 5; //最多建立5个线程数
        //新建线程池
        /*ThreadPoolExecutor(int corePoolSize,
        int maximumPoolSize,
        long keepAliveTime,
        TimeUnit unit,
        BlockingQueue<Runnable> workQueue
        RejectedExecutionHandler handler)

        corePoolSize: 线程池维护线程的最少线程数,也是核心线程数,包括空闲线程
        maximumPoolSize: 线程池维护线程的最大线程数
        keepAliveTime: 线程池维护线程所允许的空闲时间
        unit: 程池维护线程所允许的空闲时间的单位
        workQueue: 线程池所使用的缓冲队列
        handler: 线程池对拒绝任务的处理策略*/
        ThreadPoolExecutor thexe = new ThreadPoolExecutor(2, thread,
                300, TimeUnit.MILLISECONDS, new ArrayBlockingQueue<Runnable>(3),
                new ThreadPoolExecutor.CallerRunsPolicy());
        //安排线程池
        for (int i = 0; i < thread; i++) {
            thexe.execute(new PrintStr(i, strlist));
        }
        //关闭线程池
        thexe.shutdown();
    }
}

class PrintStr implements Runnable {
    private int thnum;
    private List<String> strlist;
    public PrintStr (int thnum, List<String> strlist) {
        this.thnum = thnum;
        this.strlist = strlist;
    }
    public void run() {
        for (String str : strlist) {
            System.out.println("线程" + thnum + " " + str);
        }
    }
}