线程分配不足会导致什么问题

矫情吗；* 2024-04-17 21:02 153阅读 0赞

啥也不说，直接上代码

package offer_0831;
    
    import java.util.concurrent.*;
    
    public class ThreadOverFlow {
    
        public static void main(String[] args) {
            ExecutorService es = new ThreadPoolExecutor(2, 2, 0, TimeUnit.SECONDS, new ArrayBlockingQueue(1));
            final CountDownLatch cdl = new CountDownLatch(10);
            for (int i = 0; i < 10; i++) {
                final int finalID = i+1;
                es.submit(new Runnable() {
                    public void run() {
                        System.out.println("t num is " + finalID);
                        try {
                            Thread.sleep(finalID*1000);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        System.out.println("stop t and num is " + finalID);
                        cdl.countDown();
                    }
                });
            }
    
            System.out.println("ok ,good bye");
        }
    }

执行结果

Connected to the target VM, address: '127.0.0.1:6218', transport: 'socket'
    Exception in thread "main" java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.FutureTask@3d8c7aca rejected from java.util.concurrent.ThreadPoolExecutor@668bc3d5[Running, pool size = 2, active threads = 2, queued tasks = 1, completed tasks = 0]
    	at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2063)
    	at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:830)
    	at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1379)
    	at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:112)
    	at offer_0831.ThreadOverFlow.main(ThreadOverFlow.java:12)
    t num is 0
    t num is 1
    stop t and num is 0
    t num is 2
    stop t and num is 1
    stop t and num is 2

结论：

线程池拒绝接收线程提交