java基础之多线程闭锁
Posted
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了java基础之多线程闭锁相关的知识，希望对你有一定的参考价值。
1.闭锁方式1：利用CountDownLatch进行闭锁
import java.util.concurrent.CountDownLatch;
public class CloseLock3 {
public static void main(String[] args) {
long start = System.currentTimeMillis();
CountDownLatch latch = new CountDownLatch(5);
CountEven even = new CountEven(latch);
for (int i = 1; i <= 5; i++) {
new Thread(even).start();
}
try {
latch.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
long end = System.currentTimeMillis();
System.out.println("偶数个数为：" + even.getNum());
System.out.println("耗时为：" + (end - start));
}
}
class CountEven implements Runnable {
private int i = 100;
private boolean flag = true;
private int num;
private CountDownLatch latch;
public CountEven(CountDownLatch latch) {
super();
this.latch = latch;
}
@Override
public void run() {
try {
while (flag) {
synchronized (this) {
if (i >= 0) {
if (i % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ":" + i + "是一个偶数");
num++;
}
i--;
} else {
flag = false;
}
}
}
} finally {
latch.countDown();
}
}
public int getNum() {
return num;
}
}
2.闭锁方式2：利用Callable的返回值进行闭锁
import java.util.concurrent.Callable;
import java.util.concurrent.FutureTask;
public class CloseLock {
public static void main(String[] args) {
long start = System.currentTimeMillis();
CountEven even = new CountEven();
FutureTask<Integer> task = new FutureTask<>(new Callable<Integer>() {
@Override
public Integer call() throws Exception {
even.even();
return null;
}
});
new Thread(task, "线程1").start();
try {
task.get();//阻塞式方法
} catch (Exception e) {
e.printStackTrace();
}
long end = System.currentTimeMillis();
System.out.println("偶数个数为：" + even.getNum());
System.out.println("耗时为：" + (end - start));
}
}
class CountEven {
private int i = 100;
private boolean flag = true;
private int num;
public void even() {
while (flag) {
synchronized (this) {
if (i >= 0) {
if (i % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ":" + i + "是一个偶数");
num++;
}
i--;
} else {
flag = false;
}
}
}
}
public int getNum() {
return num;
}
}
3. 利用isalive进行闭锁
public class CloseLock {
public static void main(String[] args) {
long start = System.currentTimeMillis();
CountEven even = new CountEven();
Thread thread = new Thread(even);
thread.start();
while (thread.isAlive()) {
//thread线程没结束则一直死循环
}
long end = System.currentTimeMillis();
System.out.println("偶数个数为：" + even.getNum());
System.out.println("耗时为：" + (end - start));
}
}
class CountEven implements Runnable {
private int i = 100;
private boolean flag = true;
private int num;
@Override
public void run() {
while (flag) {
synchronized (this) {
if (i >= 0) {
if (i % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ":" + i + "是一个偶数");
num++;
}
i--;
} else {
flag = false;
}
}
}
}
public int getNum() {
return num;
}
}
4.利用线程组进行闭锁
public class CloseLock {
public static void main(String[] args) {
long start = System.currentTimeMillis();
CountEven even = new CountEven();
ThreadGroup group = new ThreadGroup("线程组1");
Thread thread = new Thread(group,even);
Thread thread1 = new Thread(group,even);
thread.start();
thread1.start();
while (group.activeCount()!=0) {//activeCount()方法主要用于测试
}
long end = System.currentTimeMillis();
System.out.println("偶数个数为：" + even.getNum());
System.out.println("耗时为：" + (end - start));
}
}
class CountEven implements Runnable {
private int i = 100;
private boolean flag = true;
private int num;
@Override
public void run() {
while (flag) {
synchronized (this) {
if (i >= 0) {
if (i % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ":" + i + "是一个偶数");
num++;
}
i--;
} else {
flag = false;
}
}
}
}
public int getNum() {
return num;
}
}
以上是关于java基础之多线程闭锁的主要内容，如果未能解决你的问题，请参考以下文章