JUnit expected exception test

Expected exception test is used for the methods which can throw an exception. We have to specify expected exception in @Test(expected = expectedException.class) action. If expected exception or any of its subclass exception is thrown by the method then JUnit will pass this unit test.

Example:

DivisionTestCase.java

import com.javawithease.business.*; import static org.junit.Assert.*; import org.junit.Test;   /** * This is test case class for division method. * @author javawithease */ public class DivisionTestCase { //DivisionTest class objects DivisionTest divisionTest1 = new DivisionTest(10, 2); DivisionTest divisionTest2 = new DivisionTest(10, 0);   //Test case for division @Test public void test() { assertEquals(5, divisionTest1.division()); }   //Test case for expected ArithmeticException, //As in this case ArithmeticException // is the expected exception so JUnit //will pass this unit test. @Test(expected = ArithmeticException.class) public void testException() { assertEquals(5, divisionTest2.division()); } }

DivisionTest.java

/** * This is simple java class containing division method. * @author javawithease */ public class DivisionTest { //data members int num1, num2;   //parameterised constructor public DivisionTest(int num1, int num2){ this.num1 = num1; this.num2 = num2; }   //division method public int division() throws ArithmeticException{ return num1/num2; } }

Output: