注意三个添加方法的区别->查API文档 拿插入来说 一个会抛异常 一个返回true/false 一个会阻塞
是记不住的 找到doc即可 把精力留出来吧
阻塞队列与Semaphore有些相似，但也不同，阻塞队列是一方存放数据，另一方释放数据，Semaphore通常则是由同一方设置和释放信号量。
用3个空间的队列来演示阻塞队列的功能和效果。
package javaplay.thread.test;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class BlockingQueueTest {
public static void main(String[] args) {
final BlockingQueue<Integer> queue = new ArrayBlockingQueue<>(3);
for (int i = 0; i < 2; i++) {
new Thread() {
public void run() {
while (true) {
try {
Thread.sleep((long) (Math.random() * 1000));
System.out.println(Thread.currentThread().getName() + "准备放数据!");
queue.put(1);
System.out.println(Thread.currentThread().getName() + "已经放了数据，" + "队列目前有" + queue.size() + "个数据");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}.start();
}
new Thread() {
public void run() {
while (true) {
try {
// 将此处的睡眠时间分别改为100和1000，观察运行结果会发现经常会有3个数据 100则因取得快很少有3
Thread.sleep(1000);
System.out.println(Thread.currentThread().getName() + "准备取数据!");
queue.take();
System.out.println(Thread.currentThread().getName() + "已经取走数据，" + "队列目前有" + queue.size() + "个数据");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}.start();
}
}
用两个具有1个空间的队列来实现同步通知的功能。
package javaplay.thread.test;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class BlockingQueueCommunication {
public static void main(String[] args) {
final Business business = new Business();
new Thread(new Runnable() {
@Override
public void run() {
for (int i = 1; i <= 5; i++) {
business.sub(i);
}
}
}).start();
for (int i = 1; i <= 5; i++) {
business.main(i);
}
}
static class Business {
BlockingQueue<Integer> queue1 = new ArrayBlockingQueue<Integer>(1);
BlockingQueue<Integer> queue2 = new ArrayBlockingQueue<Integer>(1);
{// 此处不能加static(queue1/queue2都不是static) 这叫匿名构造方法 运行时机在任何构造方法之前
// Collections.synchronizedMap(null);
try {
System.out.println("xxxxxdfsdsafdsa");
queue2.put(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public void sub(int i) {
try {
queue1.put(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
for (int j = 1; j <= 1; j++) {
System.out.println("sub thread sequece of " + j + ",loop of " + i);
}
try {
queue2.take();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public void main(int i) {// 此处不能加synchronized 否则如果main先进去就死锁了
try {
queue2.put(1);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
for (int j = 1; j <= 2; j++) {
System.out.println("main thread sequece of " + j + ",loop of " + i);
}
try {
queue1.take();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
一个队列可否实现呢？