Java单例线程池，管理线程池的创建和使用

importcn.hutool.core.thread.ThreadFactoryBuilder;
importorg.slf4j.Logger;
importorg.slf4j.LoggerFactory;
importjava.util.concurrent.*;
publicenumThreadPoolSingleton {
/*** 线程池实例*/INSTANCE;
privatefinalThreadPoolExecutorexecutor;
privatefinalLoggerlogger=LoggerFactory.getLogger(ThreadPoolSingleton.class);
publicThreadPoolExecutorgetInstance() {
returnexecutor;
    }
ThreadPoolSingleton() {
//记录异常ThreadFactorynamedThreadFactory=ThreadFactoryBuilder.create()
                .setNamePrefix("admin-thread-")
                .setUncaughtExceptionHandler((thread, throwable) ->logger.error("ThreadPool {} got exception", thread, throwable))
                .build();
//核心线程数大小finalintcorePoolSize=4;
//最大线程数大小,阻塞队列占满后会在线程池中继续开启新的线程,总的线程数量不会大于最大线程数finalintmaximumPoolSize=4;
//最大线程数空闲后的存活时间finallongkeepAliveTime=1L;
//最大线程数空闲后的存活时间的单位finalTimeUnittimeUnit=TimeUnit.MINUTES;
//阻塞队列,核心线程数占满后会把新入线程放入阻塞队列finalArrayBlockingQueue<Runnable>workQueue=newArrayBlockingQueue<>(10);
//拒绝策略,最大线程数占满之后会执行此策略//由调用线程（提交任务的线程）处理该任务finalThreadPoolExecutor.CallerRunsPolicycallerRunsPolicy=newThreadPoolExecutor.CallerRunsPolicy();
//丢弃任务并抛出RejectedExecutionException异常//final ThreadPoolExecutor.CallerRunsPolicy CALLER_RUNS_POLICY = new ThreadPoolExecutor.AbortPolicy();//丢弃任务，不抛异常//final ThreadPoolExecutor.CallerRunsPolicy CALLER_RUNS_POLICY = new ThreadPoolExecutor.DiscardPolicy();//丢弃队列中最老的一个请求，也就是即将被执行的一个任务，并尝试再次提交当前任务//final ThreadPoolExecutor.CallerRunsPolicy CALLER_RUNS_POLICY = new ThreadPoolExecutor.DiscardOldestPolicy();executor=newThreadPoolExecutor(corePoolSize, maximumPoolSize, keepAliveTime, timeUnit, workQueue, namedThreadFactory, callerRunsPolicy);
    }
/*** 需要获取返回值调用此方法** @Param callable* @param <T>* @return*/publicstatic<T>Future<T>submit(Callable<T>callable) {
returnINSTANCE.getInstance().submit(callable);
    }
/*** 不需要获取返回值调用此方法** @param runnable*/publicstaticvoidexecute(Runnablerunnable) {
INSTANCE.getInstance().execute(runnable);
    }
}

importjava.util.concurrent.Callable;
importjava.util.concurrent.ExecutionException;
importjava.util.concurrent.Future;
publicclassMain {
publicstaticvoidmain(String[] args) {
// 创建一个 Callable 任务Callable<Integer>callable=newCallable<Integer>() {
@OverridepublicIntegercall() throwsException {
// 执行耗时操作，并返回结果returnlongRunningTask();
            }
        };
// 提交任务并获取 Future 对象Future<Integer>future=ThreadPoolSingleton.submit(callable);
try {
// 阻塞等待任务执行完成并获取结果intresult=future.get();
System.out.println("任务执行结果: "+result);
        } catch (InterruptedException|ExecutionExceptione) {
e.printStackTrace();
        }
    }
privatestaticintlongRunningTask() {
// 执行耗时操作，这里假设返回一个数值return42;
    }
}

publicclassMain {
publicstaticvoidmain(String[] args) {
// 创建一个实现了 Runnable 接口的任务Runnablerunnable=newRunnable() {
@Overridepublicvoidrun() {
// 执行耗时操作longRunningTask();
            }
        };
// 提交任务ThreadPoolSingleton.execute(runnable);
    }
privatestaticvoidlongRunningTask() {
// 执行耗时操作System.out.println("任务执行中...");
    }
}