java单元测试JUnit框架原理与用法实例教程

/**
* JUnit 注解示例
*/
@Test
public void testYeepay(){
  Syetem.out.println("用@Test标示测试方法！");
}
@AfterClass
public static void paylus(){
  Syetem.out.println("用@AfterClass标示的方法在测试用例类执行完之后！");
}

/**
* 用 JUnit 3.X 进行测试
*/
import junit.framework.Assert;
import junit.framework.TestCase;
public class TestOperation extends TestCase {
  private Operation operation;
  public TestOperation(String name) { // 构造函数
    super(name);
  }
  @Override
  public void setUp() throws Exception { // 在每个测试方法执行 [之前] 都会被调用，多用于初始化
    System.out.println("欢迎使用Junit进行单元测试...");
    operation = new Operation();
  }
  @Override
  public void tearDown() throws Exception { // 在每个测试方法执行 [之后] 都会被调用，多用于释放资源
    System.out.println("Junit单元测试结束...");
  }
  public void testDivideByZero() {
    Throwable te = null;
    try {
      operation.divide(6, 0);
      Assert.fail("测试失败"); //断言失败
    } catch (Exception e) {
      e.printStackTrace();
      te = e;
    }
    Assert.assertEquals(Exception.class, te.getClass());
    Assert.assertEquals("除数不能为 0 ", te.getMessage());
  }
}

/**
* 用 JUnit 4.X 进行测试
*/
import static org.junit.Assert.*;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
public class TestOperation {
  private Operation operation;
  @BeforeClass
  public static void globalInit() { // 在所有方法执行之前执行
    System.out.println("@BeforeClass标注的方法，在所有方法执行之前执行...");
  }
  @AfterClass
  public static void globalDestory() { // 在所有方法执行之后执行
    System.out.println("@AfterClass标注的方法，在所有方法执行之后执行...");
  }
  @Before
  public void setUp() { // 在每个测试方法之前执行
    System.out.println("@Before标注的方法，在每个测试方法之前执行...");
    operation = new Operation();
  }
  @After
  public void tearDown() { // 在每个测试方法之后执行
    System.out.println("@After标注的方法，在每个测试方法之后执行...");
  }
  @Test(timeout=600)
  public void testAdd() { // 设置限定测试方法的运行时间 如果超出则返回错误
    System.out.println("测试 add 方法...");
    int result = operation.add(2, 3);
    assertEquals(5, result);
  }
  @Test
  public void testSubtract() {
    System.out.println("测试 subtract 方法...");
    int result = operation.subtract(1, 2);
    assertEquals(-1, result);
  }
  @Test
  public void testMultiply() {
    System.out.println("测试 multiply 方法...");
    int result = operation.multiply(2, 3);
    assertEquals(6, result);
  }
  @Test
  public void testDivide() {
    System.out.println("测试 divide 方法...");
    int result = 0;
    try {
      result = operation.divide(6, 2);
    } catch (Exception e) {
      fail();
    }
    assertEquals(3, result);
  }
  @Test(expected = Exception.class)
  public void testDivideAgain() throws Exception {
    System.out.println("测试 divide 方法，除数为 0 的情况...");
    operation.divide(6, 0);
    fail("test Error");
  }
  public static void main(String[] args) {
  }
}

/**
* 定义了加减乘除的法则
*/
public class Operation {
  public static void main(String[] args) {
    System.out.println("a + b = " + add(1,2));
    System.out.println("a - b = " + subtract(1,2));
    System.out.println("a * b = " + multiply(1,2));
    System.out.println("a / b = " + divide(4,2));
    System.out.println("a / b = " + divide(1,0));
  }
  public static int add(int a, int b) {
    return a + b;
  }
  public static int subtract(int a, int b) {
    return a - b;
  }
  public static int multiply(int a, int b) {
    return a * b;
  }
  public static int divide(int a, int b) {
    return a / b;
  }
}

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import java.util.ArrayList;
import java.util.Collection;
/**
 * 1、创建一个测试类，继承TestCase类
 */
public class SimpleTestDemo extends TestCase {
  public SimpleTestDemo(String name) {
    super(name);
  }
  /**
   * 2、写一个测试方法，断言期望的结果
   */
  public void testEmptyCollection(){
    Collection collection = new ArrayList();
    assertTrue(collection.isEmpty());
  }
  /**
   * 3、写一个suite()方法，它会使用反射动态的创建一个包含所有的testXxxx方法的测试套件
   */
  public static Test suit(){
    return new TestSuite(SimpleTestDemo.class);
  }
  /**
   * 4、写一个main()方法，以文本运行器的方式方便的运行测试
   */
  public static void main(String[] args) {
    junit.textui.TestRunner.run(suit());
  }
}

/**
* 待测试类
*/
import java.util.Arrays;
public class GotoWork {
  public String[] prepareSkills() {
    String[] skill = { "Java", "MySQL", "JSP" };
    System.out.println("My skills include : " + Arrays.toString(skill));
    return skill;
  }
  public String[] addSkills() {
    String[] skill = { "Java", "MySQL", "JSP", "JUnit" };
    System.out.println("Look, my skills include : " + Arrays.toString(skill));
    return skill;
  }
}

/**
* 测试类 1
*/
import org.junit.Test;
import static org.junit.Assert.*;
public class PrepareSkillsTest {
  GotoWork gotoWork = new GotoWork();
  String[] skill = { "Java", "MySQL", "JSP" };
  @Test
  public void testPrepareSkills() {
    System.out.println("Inside testPrepareSkills()");
    assertArrayEquals(skill, gotoWork.prepareSkills());
  }
}

/**
* 测试类 2
*/
import org.junit.Test;
import static org.junit.Assert.*;
public class AddSkillsTest {
  GotoWork gotoWork = new GotoWork();
  String[] skill = { "Java", "MySQL", "JSP", "JUnit" };
  @Test
  public void testAddSkills() {
    System.out.println("Inside testAddPencils()");
    assertArrayEquals(skill, gotoWork.addSkills());
  }
}

/**
* 套件测试
*/
import org.junit.runner.RunWith;
import org.junit.runners.Suite;
@RunWith(Suite.class)
@Suite.SuiteClasses({ PrepareSkillsTest.class, AddSkillsTest.class })
public class SuitTest {
}

/**
* 待测试类
*/
public class Calculate {
  public int sum(int var1, int var2) {
    System.out.println("此方法的参数值分别为 : " + var1 + " + " + var2);
    return var1 + var2;
  }
}

/**
* 参数化测试类
*/
import static org.junit.Assert.assertEquals;
import java.util.Arrays;
import java.util.Collection;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;
@RunWith(Parameterized.class)
public class CalculateTest {
  private int expected;
  private int first;
  private int second;
  public CalculateTest(int expectedResult, int firstNumber, int secondNumber) {
    this.expected = expectedResult;
    this.first = firstNumber;
    this.second = secondNumber;
  }
  @Parameters
  public static Collection addedNumbers() {
    return Arrays.asList(new Integer[][] { { 3, 1, 2 }, { 5, 2, 3 }, { 7, 3, 4 }, { 9, 4, 5 }, });
  }
  @Test
  public void testSum() {
    Calculate add = new Calculate();
    System.out.println("Addition with parameters : " + first + " and " + second);
    assertEquals(expected, add.sum(first, second));
  }
}