Question

What is the difference between @BeforeClass and @BeforeTest in TestNG?

Answer 1

Hi Mithun, @BeforeTest method runs before any test method, belonging to the classes inside the tag, is run. While @BeforeClass method runs before the first test method in the current class is invoked. For eg: this TestNGAnnotations.java file will test annotations:

public class TestNGAnnotations {
   // test case 1
   @Test
   public void testCase1() {
      System.out.println("Test case 1");
   }

   // test case 2
   @Test
   public void testCase2() {
      System.out.println("Test case 2");
   }

   @BeforeClass
   public void beforeClass() {
      System.out.println("BeforeClass");
   }

   @BeforeTest
   public void beforeTest() {
      System.out.println("BeforeTest");
   }

}

Now create the file testng.xml to execute testng annotations:

<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >

<suite name = "Suite1">
   <test name = "Test1">
      <classes>
         <class name = "TestNGAnnotations"/>
      </classes>
   </test>
</suite>

​Now, run the testng.xml, which will run the test case and produce following output:

BeforeTest
BeforeClass
Test case 1
Test case 2

===============================================
Suite
Total tests run: 2, Failures: 0, Skips: 0
===============================================