Java的多线程操作

需要执行多线程操作（对某个方法执行）

1. 执行方法不固定，参数不固定，返回类型不固定（当前是固定的）。

2. 在已有的项目上做迭代，要求改动越小越好。

/**
   * 执行多线程操作 默认：20线程 30S最大等待时间 异常不抛出
   *
   * @param param 参数List
   * @param function 函数<Object, Result>
   */
  public List<Object> multiThreadSpiderFunc(List<Object> param, Function<Object, Result> function)
      throws Exception {
    return multiThreadFunc(param, function, 20, 30, Boolean.FALSE);
  }

  public List<Object> multiThreadFunc(List<Object> param, Function<Object, Result> function,
      Integer maxThreadPool, Integer maxWaitTime, Boolean throwException) throws Exception {
    Integer size = maxThreadPool;
    ExecutorService threadPool = Executors.newFixedThreadPool(size);
    List<Future> futureList = new ArrayList<>(size);

    for (Integer i = 0; i < param.size(); i++) {
      Callable callableThread = new CallableThread(param.get(i), function);
      Future f = threadPool.submit(callableThread);
      futureList.add(f);
    }
    List<Object> resultList = new ArrayList();
    // 获取所有并发结果
    for (Future future : futureList) {
      try {
        resultList.add(future.get(maxWaitTime, TimeUnit.SECONDS));
      } catch (InterruptedException e) {
        //中断异常
        logger().println("中断异常：" + e);
      } catch (ExecutionException e) {
        //程序抛出异常
        logger().println("程序抛出异常：" + e);
        if (throwException) {
          //线程池销毁
          threadPool.shutdownNow();
          throw e;
        }
      } catch (TimeoutException e) {
        //超时异常
        logger().println("超时异常：" + e);
      } finally {
        future.cancel(true);
      }
    }
    threadPool.shutdown();
    return resultList;
  }

  public class CallableThread implements Callable {

    /**
     * 多线程参数
     */
    volatile Object param;
    /**
     * 函数
     */
    volatile Function<Object, Result> function;

    public CallableThread(Object param, Function<Object, Result> function) {
      this.param = param;
      this.function = function;
    }

    @Override
    public Result call() {
      try {
        ThreadSpiderParam paramObj = (ThreadSpiderParam) param;
        Thread.currentThread().setName(paramObj.getThreadName());
      } catch (Exception e) {
        logger().println(e);
        logger().println("设置线程名称异常 使用系统默认命名");
      }

      return function.apply(param);
    }
  }

多线程的基础学习 参考：https://www.cnblogs.com/yishilin/p/8436303.html