到目前为止,我们已经使用注释来创建模拟. Mockito提供了各种方法来创建模拟对象. mock()创建模拟而不会打扰模拟将在其操作过程中进行的方法调用的顺序.
语法
calcService = mock(CalculatorService.class);
示例
步骤1号;创建一个名为CalculatorService的接口来提供数学函数
文件:CalculatorService.java
public interface CalculatorService { public double add(double input1, double input2); public double subtract(double input1, double input2); public double multiply(double input1, double input2); public double divide(double input1, double input2);}
第2步去;创建一个JAVA类来表示MathApplication
文件:MathApplication.java
public class MathApplication { private CalculatorService calcService; public void setCalculatorService(CalculatorService calcService){ this.calcService = calcService; } public double add(double input1, double input2){ return calcService.add(input1, input2); } public double subtract(double input1, double input2){ return calcService.subtract(input1, input2); } public double multiply(double input1, double input2){ return calcService.multiply(input1, input2); } public double divide(double input1, double input2){ return calcService.divide(input1, input2); }}
第3步和第3步;测试MathApplication类
让我们通过在其中注入一个模拟的calculatorService来测试MathApplication类.模拟将由Mockito创建.
这里我们通过when()向模拟对象添加了两个模拟方法调用add()和subtract().但是在测试期间,我们在调用add()之前调用了subtract().当我们使用create()创建一个模拟对象时,该方法的执行顺序无关紧要.
文件:MathApplicationTester.java
package com.it1352.mock; import static org.mockito.Mockito.mock;import static org.mockito.Mockito.verify;import static org.mockito.Mockito.when;import org.junit.Assert;import org.junit.Before;import org.junit.Test;import org.junit.runner.RunWith;import org.mockito.runners.MockitoJUnitRunner;// @RunWith attaches a runner with the test class to initialize the test data@RunWith(MockitoJUnitRunner.class)public class MathApplicationTester { private MathApplication mathApplication; private CalculatorService calcService; @Before public void setUp(){ mathApplication = new MathApplication(); calcService = mock(CalculatorService.class); mathApplication.setCalculatorService(calcService); } @Test public void testAddAndSubtract(){ //add the behavior to add numbers when(calcService.add(20.0,10.0)).thenReturn(30.0); //subtract the behavior to subtract numbers when(calcService.subtract(20.0,10.0)).thenReturn(10.0); //test the subtract functionality Assert.assertEquals(mathApplication.subtract(20.0, 10.0),10.0,0); //test the add functionality Assert.assertEquals(mathApplication.add(20.0, 10.0),30.0,0); //verify call to calcService is made or not verify(calcService).add(20.0,10.0); verify(calcService).subtract(20.0,10.0); }}
步骤4 : 执行测试用例
在 C:\>中创建名为TestRunner的java类文件Mockito_WORKSPACE 执行测试用例.
文件:TestRunner.java
import org.junit.runner.JUnitCore;import org.junit.runner.Result;import org.junit.runner.notification.Failure;public class TestRunner { public static void main(String[] args) { Result result = JUnitCore.runClasses(MathApplicationTester.class); for (Failure failure : result.getFailures()) { System.out.println(failure.toString()); } System.out.println(result.wasSuccessful()); }}
第5步去;验证结果
使用 javac 编译器编译类,如下所示 :
C:\Mockito_WORKSPACE>javac CalculatorService.java MathApplication. java MathApplicationTester.java TestRunner.java
现在运行Test Runner查看结果 :
C:\Mockito_WORKSPACE>java TestRunner
验证输出.
true