如何将主要方法移动到另一个类在Scala？ [英] How to move main method to another class in Scala?

问题描述

IntelliJ IDEA 10.5（可能这是重要的）。

IntelliJ IDEA 10.5 (probably this matters).

我是Scala的新人，所以我开始以一种akward的方式。我创建了一个文件与两个类 - 空MainApp和另一个类，HelloWorld与方法main。

I am new to Scala, so I started in an akward way. I created one file with two classes -- empty MainApp and another class, HelloWorld with method main.

我编译并执行IntelliJ自动检测HelloWorld作为主类。

I compiled it and executed -- IntelliJ automatically detected HelloWorld as main class. It was OK.

然后，我将main方法移动到MainApp，并删除（然后清空）HelloWorld类。当我试图运行它，IntelliJ坚持到HelloWorld。所以我重新配置项目并选择MainApp作为主类。

Then, I moved main method to MainApp, and deleted (then empty) HelloWorld class. When I tried to run it, IntelliJ sticked to HelloWorld nevertheless. So I reconfigured project and selected MainApp as main class.

我试图用这样的结果运行它：

I tried to run it with such result:

MainApp main方法应该是静态的

MainApp main method should be static

我完全感到困惑。首先，Scala没有静态方法。第二，为什么它不编译现在，当它编译之前（与HelloWorld类）。

I am completely puzzled. First of all, Scala does not have static methods. Second of all, why it does not compile now, when it compiled before (with HelloWorld class). I though that only requirement is having one main method.

预先感谢您的帮助。

推荐答案

Java中的静态方法大致对应于Scala中的单例方法。您应该有

static methods in Java roughly correspond to singleton methods in Scala. You should have

object MainApp {
  def main(args : Array[String]) = ...
}

，而不是 class MainApp 。

这篇关于如何将主要方法移动到另一个类在Scala？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！