JUnit – Basic annotation examples

Here’re some basic JUnit annotations you should understand:

1.@BeforeClass – Run once before any of the test methods in the class, public static void

2.@AfterClass – Run once after all the tests in the class have been run, public static void

3.@Before – Run before @Test, public void

4.@After – Run after @Test,** public void**

5.@Test – This is the test method to run,** public void**

P.S Tested with JUnit 4.12

BasicAnnotationTest.java

package com.mkyong;

import org.junit.*;

public class BasicAnnotationTest {

    // Run once, e.g. Database connection, connection pool
    @BeforeClass
    public static void runOnceBeforeClass() {
        System.out.println("@BeforeClass - runOnceBeforeClass");
    }

    // Run once, e.g close connection, cleanup
    @AfterClass
    public static void runOnceAfterClass() {
        System.out.println("@AfterClass - runOnceAfterClass");
    }

    // Should rename to @BeforeTestMethod
    // e.g. Creating an similar object and share for all @Test
    @Before
    public void runBeforeTestMethod() {
        System.out.println("@Before - runBeforeTestMethod");
    }

    // Should rename to @AfterTestMethod
    @After
    public void runAfterTestMethod() {
        System.out.println("@After - runAfterTestMethod");
    }

    @Test
    public void test_method_1() {
        System.out.println("@Test - test_method_1");
    }

    @Test
    public void test_method_2() {
        System.out.println("@Test - test_method_2");
    }

}

輸出結果:

@BeforeClass - runOnceBeforeClass

@Before - runBeforeTestMethod
@Test - test_method_1
@After - runAfterTestMethod

@Before - runBeforeTestMethod
@Test - test_method_2
@After - runAfterTestMethod

@AfterClass - runOnceAfterClass