[Java] 聊聊Java中是什么方法导致的线程阻塞

@Component
public class Calculation {
  public Result cal(String req, int a, int b) {
  System.out.println("请求id:" + req + "  结果:" + (a + b));
  return new Result(req, a + b);
  }
}

@Component
public class SomethingElse {
  public void doElse(Result result) {
  try {
    System.out.println(Thread.currentThread().getName() + " : 开始做其他事情,请求号:" + result.getReq() + " ,请求结果:" + result.getSum());
    Thread.sleep(2000);
    System.out.println(Thread.currentThread().getName() + " : 完成做其他事情,请求号:" + result.getReq() + " ,请求结果:" + result.getSum());
  } catch (InterruptedException e) {
  }
  }
}

public class CallTask implements Callable<Result> {
  private String req;
  private int a;
  private int b;
  @Override
  public Result call() throws Exception {
  Calculation calculation = Main.applicationContext.getBean(Calculation.class);
  return calculation.cal(req, a, b);
  }
  public CallTask(String req, int a, int b) {
  this.req = req;
  this.a = a;
  this.b = b;
  }
  // getter and setter 等等
}

public class ElseTask implements Runnable {
  private CompletionService<Result> cs;
  private int threadCount;
  public ElseTask(CompletionService<Result> cs, int threadCount) {
  this.cs = cs;
  this.threadCount = threadCount;
  }
  @Override
  public void run() {
  SomethingElse somethingElse = Main.applicationContext.getBean(SomethingElse.class);
  doElse(somethingElse);
  }
  private void doElse(SomethingElse somethingElse) {
  try {
    for (int i = 0; i < threadCount; i++) {
    Future<Result> take = cs.take();
    Result result = take.get();
    somethingElse.doElse(result);
    }
  } catch (Exception e) {
  }
  }
  // getter and setter 等等
}

@Service
public class Main implements ApplicationContextAware {
  public static ApplicationContext applicationContext = null;
  public static void main(String[] args) throws InterruptedException {
  AbstractApplicationContext appContext = new ClassPathXmlApplicationContext("application01.xml");
  ExecutorService executorService = Executors.newFixedThreadPool(100);
  CompletionService<Result> cs = new ExecutorCompletionService(executorService);
  //这里启动执行计算的线程
  cs.submit(new CallTask("req001", 0, 1));
  cs.submit(new CallTask("req002", 0, 2));
  cs.submit(new CallTask("req003", 0, 3));
  cs.submit(new CallTask("req004", 0, 4));
  cs.submit(new CallTask("req005", 0, 5));
  //专门的监控线程，并执行其他耗时的线程
  executorService.execute(new ElseTask(cs, 5));
  executorService.shutdown();
  appContext.registerShutdownHook();
  }
  @Override
  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
  this.applicationContext = applicationContext;
  }
}