Mockito提供了在真实物体上创建间谍的选项.调用spy时,会调用实际对象的实际方法.
//创建实际对象的间谍 calcService = spy(calculator); //对真实对象执行操作 //测试添加功能 Assert.assertEquals(mathApplication.add(20.0,10.0),30.0,0);
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()添加了一个模拟方法调用,add()到模拟对象.但是在测试期间,我们在调用add()之前调用了subtract().当我们使用Mockito.createStrictMock()创建一个模拟对象时,该方法的执行顺序很重要.
文件:MathApplicationTester.java
import static org.mockito.Mockito.spy; 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(); Calculator calculator = new Calculator(); calcService = spy(calculator); mathApplication.setCalculatorService(calcService); } @Test public void testAdd(){ //perform operation on real object //test the add functionality Assert.assertEquals(mathApplication.add(20.0, 10.0),30.0,0); } class Calculator implements CalculatorService { @Override public double add(double input1, double input2) { return input1 + input2; } @Override public double subtract(double input1, double input2) { throw new UnsupportedOperationException("Method not implemented yet!"); } @Override public double multiply(double input1, double input2) { throw new UnsupportedOperationException("Method not implemented yet!"); } @Override public double divide(double input1, double input2) { throw new UnsupportedOperationException("Method not implemented yet!"); } } }
步骤4去;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