JAVA线程池自定义拒绝策略

男娘i 2022-03-25 08:58 797阅读 0赞

**在java线程池中实现自定义拒绝策略，只需要实现RejectedExecutionHandler接口就可以了。**

package com.bjsxt.height.concurrent018;
    import java.net.HttpURLConnection;
    import java.util.concurrent.RejectedExecutionHandler;
    import java.util.concurrent.ThreadPoolExecutor;
    public class MyRejected implements RejectedExecutionHandler{
    	public MyRejected(){
    	}
    	
    	@Override
    	public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
    		System.out.println("自定义处理..");
    		System.out.println("当前被拒绝任务为：" + r.toString());
    		
    	}
    }

**辅助测试类**

package com.bjsxt.height.concurrent018;
    
    public class MyTask implements Runnable {
    
    	private int taskId;
    	private String taskName;
    	
    	public MyTask(int taskId, String taskName){
    		this.taskId = taskId;
    		this.taskName = taskName;
    	}
    	
    	public int getTaskId() {
    		return taskId;
    	}
    
    	public void setTaskId(int taskId) {
    		this.taskId = taskId;
    	}
    
    	public String getTaskName() {
    		return taskName;
    	}
    
    	public void setTaskName(String taskName) {
    		this.taskName = taskName;
    	}
    
    	@Override
    	public void run() {
    		try {
    			System.out.println("run taskId =" + this.taskId);
    			Thread.sleep(5*1000);
    			//System.out.println("end taskId =" + this.taskId);
    		} catch (InterruptedException e) {
    			e.printStackTrace();
    		}		
    	}
    	
    	public String toString(){
    		return Integer.toString(this.taskId);
    	}
    
    }

**main方法测试类**

import java.util.concurrent.ArrayBlockingQueue;
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    import java.util.concurrent.LinkedBlockingQueue;
    import java.util.concurrent.ThreadPoolExecutor;
    import java.util.concurrent.ThreadPoolExecutor.DiscardOldestPolicy;
    import java.util.concurrent.TimeUnit;
    import java.util.concurrent.ThreadPoolExecutor.CallerRunsPolicy;
    public class UseThreadPoolExecutor1 {
    	public static void main(String[] args) {
    		/**
    		 * 在使用有界队列时，若有新的任务需要执行，如果线程池实际线程数小于corePoolSize，则优先创建线程，
    		 * 若大于corePoolSize，则会将任务加入队列，
    		 * 若队列已满，则在总线程数不大于maximumPoolSize的前提下，创建新的线程，
    		 * 若线程数大于maximumPoolSize，则执行拒绝策略。或其他自定义方式。
    		 * 
    		 */	
    		ThreadPoolExecutor pool = new ThreadPoolExecutor(
    				1, 				//coreSize
    				2, 				//MaxSize
    				60, 			//60
    				TimeUnit.SECONDS, 
    				new ArrayBlockingQueue<Runnable>(3)			//指定一种队列 （有界队列）
    				//new LinkedBlockingQueue<Runnable>()
    				, new MyRejected()
    				//, new DiscardOldestPolicy()
    				);
    		MyTask mt1 = new MyTask(1, "任务1");
    		MyTask mt2 = new MyTask(2, "任务2");
    		MyTask mt3 = new MyTask(3, "任务3");
    		MyTask mt4 = new MyTask(4, "任务4");
    		MyTask mt5 = new MyTask(5, "任务5");
    		MyTask mt6 = new MyTask(6, "任务6");
    		pool.execute(mt1);
    		pool.execute(mt2);
    		pool.execute(mt3);
    		pool.execute(mt4);
    		pool.execute(mt5);
    		pool.execute(mt6);
    		pool.shutdown();
    		
    	}
    }