1、ArrayBlockingQueue阻塞队列
- 什么情况下,我们会使用阻塞队列: 多线程并发处理,线程池!
- 添加、移除
四组API
- 1、抛出异常
- 2、不会抛出异常
- 3、阻塞等待
- 4、超时等待
package bq;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
/**
* @ProjectName: www-ES-Api
* @Package: bq
* @ClassName: BLockingQueueTest
* @Author: 125827
* @Description: BLockingQueue
* @Date: 1/12/2022 12:23 AM
* @Version: 1.0
*/
public class BlockingQueueTest {
public static void main(String[] args) throws InterruptedException {
QueueTest3();
}
/** 抛出异常 */
public static void ExceptionQueue(){
BlockingQueue queue = new ArrayBlockingQueue<>(3);
boolean a = queue.add("A");
boolean b = queue.add("B");
boolean c = queue.add("S");
System.out.println(a+"---"+b+"---"+c);
/** 队首无元素时,抛出异常java.util.NoSuchElementException*/
System.out.println(queue.element());
/** 元素个数超过队列长度,则报 java.lang.IllegalStateException: Queue full */
Object remove = queue.remove("B");
System.out.println(remove);
System.out.println(queue.remove()+"---"+queue.remove());
/** 删除时队列为空,返回java.util.NoSuchElementException
queue.remove(); */
}
/** 不抛出异常,有返回值 */
public static void QueueTest1(){
BlockingQueue queue = new ArrayBlockingQueue<>(3);
boolean a = queue.offer("A");
boolean b = queue.offer("B");
boolean c = queue.offer("S");
System.out.println(a+"---"+b+"---"+c);
System.out.println(queue.offer("c"));
/** 元素个数超过队列长度,不抛出异常 ,直接返回 false*/
Object remove = queue.poll();
System.out.println(remove);
System.out.println(queue.poll()+"---"+queue.poll());
/** 删除时队列为空,不抛出异常 ,直接返回null*/
System.out.println(queue.poll());
/** 队首无元素时,不抛出异常 ,直接返回null */
System.out.println(queue.peek());
}
/** 等待,阻塞,并一直阻塞 */
public static void QueueTest2() throws InterruptedException {
BlockingQueue queue = new ArrayBlockingQueue<>(3);
queue.put("A");
queue.put("B");
queue.put("S");
// queue.put("c");
/** 元素个数超过队列长度,阻塞 */
Object remove = queue.take();
System.out.println(remove);
System.out.println(queue.take()+"---"+queue.take());
/** 删除时队列为空,阻塞*/
// System.out.println(queue.take());
}
/** 阻塞,超时等待 */
public static void QueueTest3() throws InterruptedException {
BlockingQueue queue = new ArrayBlockingQueue<>(3);
boolean a = queue.offer("A");
boolean b = queue.offer("B");
boolean c = queue.offer("S");
System.out.println(a+"---"+b+"---"+c);
System.out.println(queue.offer("c",2, TimeUnit.SECONDS));
/** 元素个数超过队列长度,不抛出异常 ,超时等待两秒,返回 false*/
Object remove = queue.poll();
System.out.println(remove);
System.out.println(queue.poll()+"---"+queue.poll());
/** 删除时队列为空,不抛出异常 ,超时等待两秒,返回null*/
System.out.println(queue.poll(2,TimeUnit.SECONDS));
}
}
2、SynchronousQueue同步队列
- 没有容量,进去一个元素,必须等待取出来之后,才能再往里面放一个元素
- put、 take
package bq;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.TimeUnit;
/**
* @ProjectName: www-ES-Api
* @Package: bq
* @ClassName: SynchronousQueueTest
* @Author: 125827
* @Description: SynchronousQueue
* @Date: 1/12/2022 1:23 AM
* @Version: 1.0
*/
public class SynchronousQueueTest {
public static void main(String[] args) {
SynchronousQueue<String> queue = new SynchronousQueue<>();
new Thread(()->{
try {
System.out.println(Thread.currentThread().getName()+"put 1");
queue.put("1");
System.out.println(Thread.currentThread().getName()+"put 2");
queue.put("2");
System.out.println(Thread.currentThread().getName()+"put 3");
queue.put("3");
} catch (InterruptedException e) {
e.printStackTrace();
}
},"A").start();
new Thread(()->{
try {
TimeUnit.SECONDS.sleep(3);
System.out.println(Thread.currentThread().getName()+"take 1");
queue.take();
System.out.println(Thread.currentThread().getName()+"take 2");
queue.take();
System.out.println(Thread.currentThread().getName()+"take 3");
queue.take();
} catch (InterruptedException e) {
e.printStackTrace();
}
},"B").start();
}
}