Java：自定义线程池

一、自定义拒绝策略

package cn.edu.tju;

import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ThreadPoolExecutor;

public class MyRejectedExecutionHandler implements RejectedExecutionHandler {
    @Override
    public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
        System.out.println("before rejected...");
        r.run();
        System.out.println("after rejected......");
    }
}

二、自定义线程工厂：

package cn.edu.tju;

import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;

public class MyThreadFactory implements ThreadFactory {
    private static final AtomicInteger poolNumber = new AtomicInteger(1);
    private final ThreadGroup group;
    private final AtomicInteger threadNumber = new AtomicInteger(1);
    private final String namePrefix;

   public MyThreadFactory() {
        SecurityManager s = System.getSecurityManager();
        group = (s != null) ? s.getThreadGroup() :
                Thread.currentThread().getThreadGroup();
        namePrefix = "自定义线程池" +
                "-thread-";
    }

    public Thread newThread(Runnable r) {
        Thread t = new Thread(group, r,
                namePrefix + threadNumber.getAndIncrement(),
                0);
        if (t.isDaemon())
            t.setDaemon(false);
        if (t.getPriority() != Thread.NORM_PRIORITY)
            t.setPriority(Thread.NORM_PRIORITY);
        return t;
    }
}

三、继承ThreadPoolExecutor来实现自定义线程池

package cn.edu.tju;

import java.util.concurrent.*;

public class MyThreadPoolExecutor extends ThreadPoolExecutor {
    public MyThreadPoolExecutor(int corePoolSize,
                              int maximumPoolSize,
                              long keepAliveTime,
                              TimeUnit unit,
                              BlockingQueue<Runnable> workQueue,
                              ThreadFactory threadFactory,
                              RejectedExecutionHandler handler) {
        super(corePoolSize,maximumPoolSize,keepAliveTime,unit,workQueue,threadFactory,handler);
        }

        @Override
    public void beforeExecute(Thread t,Runnable r){
        System.out.println("before execution...");
    }

    @Override
    public void afterExecute(Runnable r, Throwable t){
        System.out.println("after execution...");
    }




}

四、测试类：

package cn.edu.tju;


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

public class MyThreadPoolTest {
    public static void main(String[] args) {
        MyThreadPoolExecutor threadPoolExecutor=new MyThreadPoolExecutor(3,3,60, TimeUnit.SECONDS,new LinkedBlockingDeque<>(5)
            , new MyThreadFactory(),new MyRejectedExecutionHandler());

        for(int i=0;i<10;i++){
            threadPoolExecutor.execute( () -> {
                System.out.println("task in executing...");
            });
        }

    }
}

五、执行结果

before rejected...
before execution...
before execution...
task in executing...
before execution...
task in executing...
after execution...
after execution...
task in executing...
after execution...
task in executing...
before execution...
task in executing...
after execution...
before execution...
task in executing...
after execution...
before execution...
task in executing...
after execution...
before execution...
task in executing...
after execution...
before execution...
task in executing...
after execution...
after rejected......
before execution...
task in executing...
after execution...