Java：测试抛出检查异常

Question

I'm trying to figure out a way to build a method that will test whether a checked exception has indeed been thrown. As I was building the following minimal working example ( CustomThrowablexxx are all custom types declared on their own files for readability):

package demos.exceptions;

public class TestExceptions {

    // This method will check whether the provided method throws exceptions
    // of the type provided.
    private static boolean throwsParticularThrowable(Runnable method,
                                                 Class<Throwable> cls){
        try {
            method.run();
        } catch(Throwable t){
            if(t.getClass().equals(cls))
                return true;
        }
        return false;
    }

    private static void methodOne() throws CustomThrowableOne {
        throw new CustomThrowableOne("methodOne() throws");
    }

    private static void methodTwo() throws CustomThrowableTwo {
        throw new CustomThrowableTwo("methodTwo() throws");
    }

    private static void methodThree() throws CustomThrowableThree {
        throw new CustomThrowableThree("methodThree() throws");
     }

    public static void main(String[] args){

        if(!throwsParticularThrowable(TestExceptions::methodOne, 
                                             CustomThrowableOne.class))
            System.out.println("Nope!");
    }
}

I unfortunately noticed that the access to TestExceptions::methodOne was not safe, because the compiler complained that I'm not checking for the throwing of methodOne , which I guess makes sense.

Is there any way I can automate this instead of copying and pasting the code inside throwsParticularThrowable every time?

Answer 1

I don't know what you are looking for but it's easier to test if exceptions are thrown using JUnit ExpectedException

https://junit.org/junit4/javadoc/4.12/org/junit/rules/ExpectedException.html