Java 如何使用单元测试测试我的自定义异常

您好，我已经为我的逻辑编写了一个测试用例，所有这些都很好地工作。然而，我不知道如何测试我的自定义异常。我的代码如下

 @Component
    public class PlaneFactory {
    
        public Plane getPlane(String planeType) {
        
            if (StringUtils.isBlank(planeType)) {
                throw new PlaneTypeNotFoundException();
            }
        
            if (planeType.equalsIgnoreCase("lightJet")) {
                return new LightJet();
        
            } else if (planeType.equalsIgnoreCase("midJet")) {
                return new MidJet();
            }
           
            else {
                 throw new InvalidPlaneTypeException();
                 }

       my custom exceptions below;


     PlaneTypeNotFoundException class below;


public class PlaneTypeNotFoundException extends RuntimeException {
    
        private static final long serialVersionUID = 4314211343358454345L;
    
        public PlaneTypeNotFoundException() {
    
            super("You have not enter anything to check a plane");
        }
    
    }
    InvalidPlaneTypeException below;



public class InvalidPlaneTypeException extends RuntimeException {
          
        public InvalidPlaneTypeException() {
    
            super("You need to enter one of following plane types : {LightJet, MidJet}");
        }
    
    }

哪些方法适合使用？我的意思是在这个场景中，我应该使用assertThrows还是只使用预期的注释

对于PlaneTypeNotFoundException，我尝试了一些在其下不起作用的方法

@Test
public void testPlaneFactory_isEmptyOrNull_ThenReturnException() {

    String planeType = "";

    LightJet lightJet= (LightJet) planeFactory.getPlane(planeType);

    assertThrows(PlaneNotFoundException.class, () -> lightJet.getType().equalsIgnoreCase(planeType), "You have not enter anything to check a plane");
}

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如果我正确地遵循您的代码，则

assertThrows（）

中的可执行lambda应该是您希望生成异常的代码：

public void testPlaneFactory_isEmptyOrNull_ThenReturnException() {
    assertThrows(PlaneNotFoundException.class, () -> planeFactory.getPlane(""));
}

如果它确实抛出异常，那么测试应该通过

第二种情况的测试将是：

void testInvalidPlaneType() {
    assertThrows(InvalidPlaneTypeException.class, () -> planeFactory.getPlane("doh"));
}

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不用担心，JUnit在测试异常时总是有点古怪。