import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;
public class ThreadPoolUtils {
private ThreadPoolExecutor pool = null;
static Integer num = 0;
/**
* 获取CPU核数
*/
private static final int CORE_POOL_SIZE = Runtime.getRuntime().availableProcessors();
private static final int MAXIMUM_POOL_SIZE = Runtime.getRuntime().availableProcessors() * 5;
/**
* 阻塞队列大小
*/
private static final int MAX_TASK_SIZE = Integer.MAX_VALUE;
/**
* IO密集线程池配置
* @return
*/
public ThreadPoolExecutor getIOInstance( ){
return getNewInstance(CORE_POOL_SIZE * 2 + 1 , MAXIMUM_POOL_SIZE,"IO",MAX_TASK_SIZE);
}
/**
* CUP密集线程池配置
* @return
*/
public ThreadPoolExecutor getCUPInstance( ){
return getNewInstance(CORE_POOL_SIZE, MAXIMUM_POOL_SIZE,"CUP",MAX_TASK_SIZE);
}
/**
* 获取对象
* @param corePoolSize 核心线程数量
* @param poolName 线程池名称
* @param maxThreadSize 最大线程数
* @param maxTaskSize 最大阻塞任务数
* @return
*/
public ThreadPoolExecutor getNewInstance(int corePoolSize,int maxThreadSize,String poolName,int maxTaskSize){
pool = createPool(corePoolSize,maxThreadSize,poolName,maxTaskSize);
if(pool==null){
throw new NullPointerException();
}else{
return pool;
}
}
/**
* 创建线程池
* @param corePoolSize 核心线程数量
* @param poolName 线程池名称
* @param maxThreadSize 最大线程数
* @param maxTaskSize 最大阻塞任务数
* @return
*/
private ThreadPoolExecutor createPool(int corePoolSize,int maxThreadSize,String poolName,int maxTaskSize){
return new ThreadPoolExecutor(corePoolSize,maxThreadSize,0,
TimeUnit.SECONDS,new LinkedBlockingQueue<>(maxTaskSize),
new CustomThreadFactory(poolName),
new RejectedExecutionHandlerImpl());
}
/**
* 线程工厂
* 给线程命名
*/
private class CustomThreadFactory implements ThreadFactory {
private final String poolName;
public CustomThreadFactory(String poolName){
this.poolName = poolName;
}
private AtomicInteger count = new AtomicInteger(0);
@Override
public Thread newThread(Runnable r) {
Thread t = new Thread(r);
String nowThreadName = "";
nowThreadName = poolName + count.addAndGet(1);
t.setName(nowThreadName);
return t;
}
}
/**
* 自定义拒绝策略
*/
private class RejectedExecutionHandlerImpl implements RejectedExecutionHandler {
@Override
public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
try{
System.out.println("重回队列");
executor.getQueue().put(r);
}catch (Exception e){
}
}
}
public static void main(String[] args){
ThreadPoolExecutor executor = new ThreadPoolUtils().getNewInstance(3,8,"test",5);
for (int i = 0;i<20;i++){
System.out.println("提交第"+i+"个任务");
executor.execute(()->{
try {
System.out.println(Thread.currentThread().getName());
TimeUnit.SECONDS.sleep(10);
synchronized (num){
System.out.println("数字为："+num++);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
});
System.out.println("提交第"+i+"个任务成功");
}
System.out.println("结束");
}
}
