Spring多线程的使用以及问题详解

@Configuration
@EnableAsync
public class ThreadPoolConfig implements AsyncConfigurer {
  /**
   * 核心线程池大小
   */
  private static final int CORE_POOL_SIZE = 3;

  /**
   * 最大可创建的线程数
   */
  private static final int MAX_POOL_SIZE = 10;

  /**
   * 队列最大长度
   */
  private static final int QUEUE_CAPACITY = 10;

  /**
   * 线程池维护线程所允许的空闲时间
   */
  private static final int KEEP_ALIVE_SECONDS = 300;

  /**
   * 异步执行方法线程池
   *
   * @return
   */
  @Override
  @Bean
  public Executor getAsyncExecutor() {
    ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
    executor.setMaxPoolSize(MAX_POOL_SIZE);
    executor.setCorePoolSize(CORE_POOL_SIZE);
    executor.setQueueCapacity(QUEUE_CAPACITY);
    executor.setKeepAliveSeconds(KEEP_ALIVE_SECONDS);
    executor.setThreadNamePrefix("LiMingTest");
    // 线程池对拒绝任务(无线程可用)的处理策略
    executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
    executor.initialize();
    return executor;
  }
}

public class TestServiceImpl implements TestService {
  private final static Logger logger = LoggerFactory.getLogger(TestServiceImpl.class);
  @Override
  public void task(int i) {
      logger.info("任务: "+i);
  }
}

@Autowired
  TestService testService;
  @Test
  public void test() {
    for (int i = 0; i < 50; i++) {
      testService.task(i);
    }

class TestServiceImplTest {
  @Test
  public void test() {
    Thread add = new AddThread();
    Thread dec = new DecThread();
    add.start();
    dec.start();
    add.join();
    dec.join();
    System.out.println(Counter.count);
  }

  static class Counter {
    public static int count = 0;
  }

  class AddThread extends Thread {
    public void run() {
      for (int i=0; i<10000; i++) { Counter.count += 1; }
    }
  }

  class DecThread extends Thread {
    public void run() {
      for (int i=0; i<10000; i++) { Counter.count -= 1; }
    }
  }

static class Counter {
    public static final Object lock = new Object();//每个线程都需获得锁才能执行
    public static int count = 0;
  }

  class AddThread extends Thread {
    public void run() {
      for (int i=0; i<10000; i++) {
        synchronized(Counter.lock) { static class Counter {
    public static final Object lock = new Object();
    public static int count = 0;
  }

  class DecThread extends Thread {
    public void run() {
      for (int i=0; i<10000; i++) {
        synchronized(Counter.lock) {
          Counter.count -= 1;
        }
      }
    }
  }