Handling exceptions

Exception handling is an important part of Java coding. The Java community follows a set of best practices about exception handling. The following are the exception handling best practices for unit testing:

• Do not write catch blocks to pass a unit test. Consider the following example where a Calculator program has a divide method. It takes two integers, divides, and returns a result. When divide encounters a divide by zero, the program should throw an exception. The following is the code:

  public class Calculator {
  
    public int divide(int op1, int op2)  {
      return op1/op2;
    }
  }

  The following is the test:

  @Test
  public void divideByZero_throws_exception() throws Exception {
    try {
      calc.divide(1, 0);
      fail("Should not reach here");
    } catch (ArithmeticException e) {
  
    }
  }

  Instead of catching ArithmeticException, we can apply the JUnit 4 pattern as follows:

    @Test(expected = ArithmeticException.class)
    public void divideByZero_throws_exception() throws Exception...