Java多线程使用
线程池效果更好, 目的如连接池.
第一个实例.
ThreadPool.java
package com.lichen.test;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
public class ThreadPool {
private static int produceTaskSleepTime = 2;
private static int consumeTaskSleepTime = 2000;
private static int produceTaskMaxNumber = 10;
public static void main(String[] args) {
// 构造一个线程池
ThreadPoolExecutor threadPool = new ThreadPoolExecutor(2, 4, 3,
TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(3),
new ThreadPoolExecutor.DiscardOldestPolicy());
for ( int i = 1; i <= produceTaskMaxNumber; i++) {
try {
// 产生一个任务，并将其加入到线程池
String task = "task@ " + i;
System.out.println( "put " + task);
threadPool.execute( new ThreadPoolTask(task));
// 便于观察，等待一段时间
Thread.sleep(produceTaskSleepTime);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
public class ThreadPool {
private static int produceTaskSleepTime = 2;
private static int consumeTaskSleepTime = 2000;
private static int produceTaskMaxNumber = 10;
public static void main(String[] args) {
// 构造一个线程池
ThreadPoolExecutor threadPool = new ThreadPoolExecutor(2, 4, 3,
TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(3),
new ThreadPoolExecutor.DiscardOldestPolicy());
for ( int i = 1; i <= produceTaskMaxNumber; i++) {
try {
// 产生一个任务，并将其加入到线程池
String task = "task@ " + i;
System.out.println( "put " + task);
threadPool.execute( new ThreadPoolTask(task));
// 便于观察，等待一段时间
Thread.sleep(produceTaskSleepTime);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
ThreadPoolTask.java
package com.lichen.test;
public class ThreadPoolTask implements Runnable {
// 保存任务所需要的数据
private Object threadPoolTaskData;
private static int consumeTaskSleepTime = 2000;
ThreadPoolTask(Object tasks) {
this.threadPoolTaskData = tasks;
}
public void run() {
// 处理一个任务，这里的处理方式太简单了，仅仅是一个打印语句
System.out.println( "start .." + threadPoolTaskData);
try {
//便于观察，等待一段时间
Thread.sleep(consumeTaskSleepTime);
} catch (Exception e) {
e.printStackTrace();
}
threadPoolTaskData = null;
}
public Object getTask() {
return this.threadPoolTaskData;
}
}
public class ThreadPoolTask implements Runnable {
// 保存任务所需要的数据
private Object threadPoolTaskData;
private static int consumeTaskSleepTime = 2000;
ThreadPoolTask(Object tasks) {
this.threadPoolTaskData = tasks;
}
public void run() {
// 处理一个任务，这里的处理方式太简单了，仅仅是一个打印语句
System.out.println( "start .." + threadPoolTaskData);
try {
//便于观察，等待一段时间
Thread.sleep(consumeTaskSleepTime);
} catch (Exception e) {
e.printStackTrace();
}
threadPoolTaskData = null;
}
public Object getTask() {
return this.threadPoolTaskData;
}
}
-------------------------------------------------------
第二个实例.
TestThreadPool.java
package com.lichen.test;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class TestThreadPool {
public static void main(String args[]) throws InterruptedException {
//只有2个线程
ExecutorService exec = Executors.newFixedThreadPool(2);
for ( int index = 0; index < 100; index++) {
Runnable run = new Runnable() {
public void run() {
long time = ( long) (Math.random() * 1000);
System.out.println( "Sleeping " + time + "ms");
try {
Thread.sleep(time);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
exec.execute(run);
} // must shutdown
exec.shutdown();
}
}
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class TestThreadPool {
public static void main(String args[]) throws InterruptedException {
//只有2个线程
ExecutorService exec = Executors.newFixedThreadPool(2);
for ( int index = 0; index < 100; index++) {
Runnable run = new Runnable() {
public void run() {
long time = ( long) (Math.random() * 1000);
System.out.println( "Sleeping " + time + "ms");
try {
Thread.sleep(time);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
exec.execute(run);
} // must shutdown
exec.shutdown();
}
}
本文转自chainli 51CTO博客，原文链接：http://blog.51cto.com/lichen/160898，如需转载请自行联系原作者
