JUnit测试控制台输入和输出 [英] JUnit test for console input and output

问题描述

我只有一个方法main。如何检查System.out.println（）并使用JUnit自动替换Scanner到输入值？

I have only one method main. How to check System.out.println() and replace Scanner to input values automatically using JUnit?

请提供一些解决方案...

P.S. Please, provide some solutions...

public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    int[] arr = new int[4];

    for (int i = 0; i < arr.length; i++) {
        arr[i] = scanner.nextInt();
    }

    for (int i = 0; i < arr.length; i++) {
        int res = 0;
        int k = 0;
        int num = arr[i];
        /*.....*/
        System.out.println(num);
    }
}

推荐答案

，提取尴尬的依赖关系，让你可以测试没有他们。将主变更为：

Ideally, extract the awkward dependencies so that you can test without them. Change main to simply:

public static void main(String[] args) {
  doWork(new Scanner(System.in), System.out);
}

// TODO: Rename to something meaningful
public static void doWork(Scanner input, PrintStream output) {
  // Remainder of code
}

（考虑使用 Writer a PrintStream c）。

(Consider using a Writer instead of a PrintStream for output.)

真的需要单元测试 main - 但你可以使用扫描器测试 doWork / code>，基于 StringReader ，并输出基于 StringWriter ，提供您想要的任何输入，检查输出。

Then you don't really need to unit test main - but you can test doWork using a Scanner based on a StringReader, and output based on a StringWriter, providing whatever input you want and checking the output.

这篇关于JUnit测试控制台输入和输出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！