单例线程池

系统管理员 2022-10-11 12:27 177阅读 0赞

package com.yhcookie;
    
    import java.util.concurrent.*;
    import java.util.concurrent.atomic.AtomicInteger;
    
    /** * 线程池 * @author yhcookie * @date 2021/4/23 18:37 */
    public class SingleThreadPoolExecutor extends ThreadPoolExecutor { 
    
        private volatile static SingleThreadPoolExecutor threadPoolExecutor = null;
    
        private SingleThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory) { 
            super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory);
        }
    
        public static SingleThreadPoolExecutor getInstance(){ 
            if (null == threadPoolExecutor){ 
                synchronized (SingleThreadPoolExecutor.class){ 
                    if (null == threadPoolExecutor){ 
                        threadPoolExecutor = new SingleThreadPoolExecutor(
                                4,
                                100,
                                60,
                                TimeUnit.SECONDS,
                                new ArrayBlockingQueue<>(50),
                                new LocalThreadFactory());
                    }
                }
            }
            return threadPoolExecutor;
        }
    
        static class LocalThreadFactory implements ThreadFactory{ 
    
            private static final AtomicInteger poolNumber = new AtomicInteger(1);
            private final ThreadGroup group;
            private final AtomicInteger threadNumber = new AtomicInteger(1);
            private final String namePrefix;
    
            LocalThreadFactory() { 
                SecurityManager s = System.getSecurityManager();
                this.group = s != null ? s.getThreadGroup() : Thread.currentThread().getThreadGroup();
                this.namePrefix = "xxxxxx-pool-" + poolNumber.getAndIncrement() + "-thread-";
            }
    
            @Override
            public Thread newThread(Runnable r) { 
                Thread t = new Thread(this.group, r, this.namePrefix + this.threadNumber.getAndIncrement(), 0L);
                if (t.isDaemon()) { 
                    t.setDaemon(false);
                }
    
                if (t.getPriority() != 5) { 
                    t.setPriority(5);
                }
    
                return t;
            }
    
        }
    
    }