This tutorial introduces the basic annotation supports that implemented in Junit 4.

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import org.junit.*;
import static org.junit.Assert.*;
import java.util.*;
 
/**
 * @author mkyong
 *
 */
public class JunitTest1 {
 
    private Collection collection;
 
    @BeforeClass
    public static void oneTimeSetUp() {
        // one-time initialization code   
    	System.out.println("@BeforeClass - oneTimeSetUp");
    }
 
    @AfterClass
    public static void oneTimeTearDown() {
        // one-time cleanup code
    	System.out.println("@AfterClass - oneTimeTearDown");
    }
 
    @Before
    public void setUp() {
        collection = new ArrayList();
        System.out.println("@Before - setUp");
    }
 
    @After
    public void tearDown() {
        collection.clear();
        System.out.println("@After - tearDown");
    }
 
    @Test
    public void testEmptyCollection() {
        assertTrue(collection.isEmpty());
        System.out.println("@Test - testEmptyCollection");
    }
 
    @Test
    public void testOneItemCollection() {
        collection.add("itemA");
        assertEquals(1, collection.size());
        System.out.println("@Test - testOneItemCollection");
    }
}

Result

@BeforeClass – oneTimeSetUp
@Before – setUp
@Test – testEmptyCollection
@After – tearDown
@Before – setUp
@Test – testOneItemCollection
@After – tearDown
@AfterClass – oneTimeTearDown

In JUnit 4, we have to declare “@BeforeClass” and “@AfterClass” method as static method.