Java线程池管理
?
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
public class ThreadPoolManager {
?
?/*
? * 将构造方法访问修饰符设为私有，禁止任意实例化。
? */
?private ThreadPoolManager() {}
?
?/*
? *实例化私有的静态成员变量线程池管理对象
? */
?private static ThreadPoolManager manager = new ThreadPoolManager();
?
? /*
?? * 线程池单例创建方法
?? */
?public static ThreadPoolManager newInstance() {
?? return manager;
?}
?
?// 线程池维护线程的最少数量
?private final static int CORE_POOL_SIZE = 3;
?
?// 线程池维护线程的最大数量
?private final static int MAX_POOL_SIZE = 10;
?
?// 线程池维护线程所允许的空闲时间
?private final static int KEEP_ALIVE_TIME = 0;
?
?// 线程池所使用的缓冲队列大小
?private final static int WORK_QUEUE_SIZE = 10;
?
?// 任务调度周期
?private final static int TASK_QOS_PERIOD = 10;
?
?// 任务缓冲队列
?private Queue<Runnable> taskQueue = new LinkedList<Runnable>();
?
? /*
?? * 线程池超出界线时将任务加入缓冲队列
?? */
?final RejectedExecutionHandler handler = new RejectedExecutionHandler() {
?? public void rejectedExecution(Runnable task, ThreadPoolExecutor executor) {
??? taskQueue.offer(task);
?? }
?};
?
? /*
?? * 将缓冲队列中的任务重新加载到线程池
?? */
?final Runnable accessBufferThread = new Runnable() {
?? public void run() {
??? if (hasMoreAcquire()) {
???? threadPool.execute(taskQueue.poll());
??? }
?? }
?};
?
? /*
?? * 创建一个调度线程池
?? */
?final ScheduledExecutorService scheduler = Executors .newScheduledThreadPool(1);
?
? /*
?? * 通过调度线程周期性的执行缓冲队列中任务
?? */
?final ScheduledFuture<?> taskHandler = scheduler.scheduleAtFixedRate(
??? accessBufferThread, 0, TASK_QOS_PERIOD, TimeUnit.MILLISECONDS);
?
? /*
?? * 线程池
?? */
?final ThreadPoolExecutor threadPool = new ThreadPoolExecutor(
??? CORE_POOL_SIZE, MAX_POOL_SIZE, KEEP_ALIVE_TIME, TimeUnit.SECONDS,
??? new ArrayBlockingQueue<Runnable>(WORK_QUEUE_SIZE), this.handler);
?
? /*
?? * 消息队列检查方法
?? */
?private boolean hasMoreAcquire() {
?? return !taskQueue.isEmpty();
?}
?
? /*
?? * 向线程池中添加任务方法
?? */
?public void addExecuteTask(Runnable task) {
?? if (task != null) {
??? threadPool.execute(task);
?? }
?}
?
?
}