ThreadPoolManager类：负责管理线程池，调用轮询的线程来访问字符串缓冲区的内容，维护缓冲区，当线程池溢出时抛出的Runnable任务被加入到字符缓冲区。
public class ThreadPoolManager { private static ThreadPoolManager tpm = new ThreadPoolManager(); // 线程池维护线程的最少数量 private final static int CORE_POOL_SIZE = 4; // 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; // 消息缓冲队列 Queue msgQueue = new LinkedList(); // 访问消息缓存的调度线程 final Runnable accessBufferThread = new Runnable() { public void run() { // 查看是否有待定请求，如果有，则创建一个新的AccessDBThread，并添加到线程池中 if( hasMoreAcquire() ) { String msg = ( String ) msgQueue.poll(); Runnable task = new AccessDBThread( msg ); threadPool.execute( task ); } } }; final RejectedExecutionHandler handler = new RejectedExecutionHandler() { public void rejectedExecution( Runnable r, ThreadPoolExecutor executor ) { System.out.println(((AccessDBThread )r).getMsg()+"消息放入队列中重新等待执行"); msgQueue.offer((( AccessDBThread ) r ).getMsg() ); } }; // 管理数据库访问的线程池 final ThreadPoolExecutor threadPool = new ThreadPoolExecutor( CORE_POOL_SIZE, MAX_POOL_SIZE, KEEP_ALIVE_TIME, TimeUnit.SECONDS, new ArrayBlockingQueue( WORK_QUEUE_SIZE ), this.handler ); // 调度线程池 final ScheduledExecutorService scheduler = Executors .newScheduledThreadPool( 1 ); final ScheduledFuture taskHandler = scheduler.scheduleAtFixedRate( accessBufferThread, 0, 1, TimeUnit.SECONDS ); public static ThreadPoolManager newInstance() { return tpm; } |
