如何测试功能打印？

I have a function which should print string. I want to test through JUnit Is really the function printing what it is supposed to print. How to do it?

我有一个应该打印字符串的功能。我想通过JUnit进行测试真的是打印它应该打印的功能。怎么做?

for example, this my function:

例如,这是我的功能:

public static void test(int a){
    System.out.println(a + "^2=" + (a*a));
}

and I want to check that for a = 3 is printing 3^2=9

我想检查a = 3是否打印3 ^ 2 = 9

Ps, I can not change the function.

Ps,我无法改变功能。

1 个解决方案

#1

Why don't you try this.Hope it will work for you.

你为什么不试试呢。希望它对你有用。

public void TestPrint {
    @Rule
    public final StandardOutputStreamLog log = new StandardOutputStreamLog();

    @Test
    public static void test(int a) {
        System.out.print(a + "^2=" + (a*a));
        assertEquals("3^2=9", log.getLog());
    }
}