LinkedBlockingQueue阻塞队列offer()操作抛出中断异常

说明

在使用LinkedBlockingQueue的offer方法时，出现了中断异常，现分析一下出现这个中断异常的原因。

会产生中断异常的Demo

import java.util.concurrent.LinkedBlockingQueue; import java.util.concurrent.TimeUnit; public class TestLinkedBlockingQueue { public static void main(String[] args) { LinkedBlockingQueue lbq = new LinkedBlockingQueue(3); for(int i = 0; i < 10; i++){ try { System.out.println(lbq); //这里用offer方法往阻塞队列里面添加对象，此方法表示若队列满了，则等待1秒，1秒后若队列还是满的，则丢弃数据。 lbq.offer(i, 1000, TimeUnit.MILLISECONDS); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } Thread.currentThread().interrupt();//如果注释掉这行代码，则此程序不会抛出异常 } } }

LinkedBlockingQueue的offer源码方法

 public boolean offer(E e, long timeout, TimeUnit unit) throws InterruptedException { if (e == null) throw new NullPointerException(); long nanos = unit.toNanos(timeout); int c = -1; final ReentrantLock putLock = this.putLock; final AtomicInteger count = this.count; putLock.lockInterruptibly(); try { while (count.get() == capacity) { if (nanos <= 0) return false; nanos = notFull.awaitNanos(nanos); } enqueue(new Node<E>(e)); c = count.getAndIncrement(); if (c + 1 < capacity) notFull.signal(); } finally { putLock.unlock(); } if (c == 0) signalNotEmpty(); return true; } //lockInterruptibly方法 public void lockInterruptibly() throws InterruptedException { sync.acquireInterruptibly(1); } //acquireInterruptibly方法 public final void acquireInterruptibly(int arg) throws InterruptedException { if (Thread.interrupted()) throw new InterruptedException(); if (!tryAcquire(arg)) doAcquireInterruptibly(arg); }

所以，当线程被标记有中断标志时，offer添加时将获取不到锁，直接抛出中断异常。