This is what I do when testing to make sure an exception has been thrown

    
    //when
    final var tripConsumer = new BusTripConsumer(inputStream);
    final Executable executable = () -> tripConsumer.deserialiseTripData();

    //then
    assertThrows(IllegalArgumentException.class, executable);

This is what I do when testing to make sure an exception has been thrown

    
    //when
    final var tripConsumer = new BusTripConsumer(inputStream);
    final Executable executable = () -> tripConsumer.deserialiseTripData();

    //then
    assertThrows(IllegalArgumentException.class, executable);

在Java 8和JUnit 5 (Jupiter)中，我们可以这样断言异常。 使用org.junit.jupiter.api.Assertions.assertThrows

public static < T extends Throwable > T assertThrows(类< T > expectedType， 可执行可执行) 断言所提供的可执行文件的执行将抛出expectedType的异常并返回该异常。 如果没有抛出异常，或者抛出了不同类型的异常，则此方法将失败。 如果您不想对异常实例执行额外的检查，只需忽略返回值。

@Test
public void itShouldThrowNullPointerExceptionWhenBlahBlah() {
    assertThrows(NullPointerException.class,
            ()->{
            //do whatever you want to do here
            //ex : objectName.thisMethodShoulThrowNullPointerExceptionForNullParameter(null);
            });
}

该方法将使用org.junit.jupiter.api中的函数接口可执行文件。

参考:

http://junit.org/junit5/docs/current/user-guide/#writing-tests-assertions http://junit.org/junit5/docs/5.0.0-M2/api/org/junit/jupiter/api/Executable.html http://junit.org/junit5/docs/5.0.0-M4/api/org/junit/jupiter/api/Assertions.html#assertThrows-java.lang.Class-org.junit.jupiter.api.function.Executable-

您可以使用assertThrows()。我的例子取自文档http://junit.org/junit5/docs/current/user-guide/

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;

....

@Test
void exceptionTesting() {
    Throwable exception = assertThrows(IllegalArgumentException.class, () -> {
        throw new IllegalArgumentException("a message");
    });
    assertEquals("a message", exception.getMessage());
}

他们在JUnit 5中改变了它(预期:InvalidArgumentException，实际:invoked method)，代码看起来像这样:

@Test
public void wrongInput() {
    Throwable exception = assertThrows(InvalidArgumentException.class,
            ()->{objectName.yourMethod("WRONG");} );
}

实际上，我认为这个特殊例子的文档中有一个错误。预期的方法是expectThrows

public static void assertThrows(
public static <T extends Throwable> T expectThrows(