import staticorg.junit.jupiter.api.Assertions.*;FooService fooService=newFooService();@TestpublicvoiddoStuff_testThrownException(){// null is passed, expected NullPointerExceptionThrowable exception=assertThrows
例如: public class AssertTest { public static void main(String[] args) { AssertTest at = new AssertTest(); try { at.assertMe(true); at.assertMe(false); } catch(AssertionError ae) { System.out.println("AsseriontError catched"); } System.out.println("go on"); } private void assert...
Exception in thread "main" java.lang.AssertionError: There are only 2 weekends in a week As we see from the above example, the expression is passed to the constructor of theAssertionErrorobject. If our assumption isfalseand assertions are enabled, an exception is thrown with an appropriate me...
使用assert关键字断言,格式如下:assert <条件> 或 assert <条件> <表达式>,如果判断结果为false,则抛出一个AssertionError,在第二种表达式中,表达式将被传入AssertionError的构造器,转换成一个消息字符串。 默认情况下,断言被禁用,需要通过运行时用-enableassertions 或 -ea选项启用: java -enableassertions MyApp。
在代码实现的时候,需要使用关键字assert,而assertion本身在程序里面就是一条语句,它的作用是对boolean表达式进行检查,正确保证这个boolean表达式在程序运行到此刻的时候为true;一旦这个boolean表达式为false的话,就说明该程序已经处于了不正确的执行状态了,系统在断言开启的情况下会根据相关情况给出警告或者退出。
As mentioned earlier, Java throws the ExceptionInInitializerError exception while maintaining a reference to the root cause: assertThatThrownBy(StaticBlock::new) .isInstanceOf(ExceptionInInitializerError.class) .hasCauseInstanceOf(ArithmeticException.class); It’s also worth mentioning that the ...
可捕获的异常又可以分为两类: (1)Check异常:直接派生自Exception的异常类,必须被捕获或再次声明抛出 (2)Runtime异常:派生自RuntimeException的异常类。使用throw语句可以随时抛出这种异常对象: throw new ArithmeticException(…); JDK1.4 以上提供了assert语句,允许程序在运行期间判断某个条件是否满足,不满足时,抛出As...
编译器会报错,错误信息类似:unreported exception UnsupportedEncodingException; must be caught or declared to be thrown,并且准确地指出需要捕获的语句是return s.getBytes("GBK");。意思是说,像UnsupportedEncodingException这样的Checked Exception,必须被捕获。
\AssertExample.java Exception in thread "main" java.lang.AssertionError: Age is less than 18 at com.howtodoinjava.core.basic.AssertExample.main(AssertExample.java:14)In the above example, look at the assertion error message. It prints ‘Age is less than 18‘ which tells the parameter ...
class); thrown.expectMessage("Expected exception message"); // 调用可能抛出异常的方法 } } 复制代码在JUnit 5中,可以使用assertThrows与Lambda表达式结合: import static org.junit.jupiter.api.Assertions.assertThrows; @Test public void testMethod() { // 验证方法是否抛出预期的异常类型和消息 Expected...