EasyMock-createMock

---

到目前为止，我们已经使用注释来创建模拟。EasyMock 提供了多种创建模拟对象的方法。EasyMock.createMock() 创建模拟，而不关心模拟在其操作过程中将要进行的方法调用的顺序。

句法

calcService = EasyMock.createMock(CalculatorService.class);

例子

步骤1：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：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);
   }
}

步骤 3：测试 MathApplication 类

让我们通过向其中注入calculatorService 的模拟来测试MathApplication 类。模拟将由 EasyMock 创建。

这里我们通过expect()向模拟对象添加了两个模拟方法调用add()和subtract()。然而在测试过程中，我们在调用 add() 之前调用了 minus()。当我们使用 EasyMock.createMock() 创建模拟对象时，方法的执行顺序并不重要。

文件：MathApplicationTester.java

import org.easymock.EasyMock;
import org.easymock.EasyMockRunner;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

@RunWith(EasyMockRunner.class)
public class MathApplicationTester {
   private MathApplication mathApplication;
   private CalculatorService calcService;
   
   @Before
   public void setUp(){
      mathApplication = new MathApplication();
      calcService = EasyMock.createMock(CalculatorService.class);
      mathApplication.setCalculatorService(calcService);
   }
   @Test
   public void testAddAndSubtract(){
      //add the behavior to add numbers
      EasyMock.expect(calcService.add(20.0,10.0)).andReturn(30.0);
      
      //subtract the behavior to subtract numbers
      EasyMock.expect(calcService.subtract(20.0,10.0)).andReturn(10.0);
      
      //activate the mock
      EasyMock.replay(calcService);	
	
      //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
      EasyMock.verify(calcService);
   }
}

步骤 4：执行测试用例

在C:\> EasyMock_WORKSPACE中创建一个名为 TestRunner 的 java 类文件来执行测试用例。

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：验证结果

使用javac编译器编译类，如下所示 -

C:\EasyMock_WORKSPACE>javac MathApplicationTester.java

现在运行测试运行程序来查看结果 -

C:\EasyMock_WORKSPACE>java TestRunner

输出

验证输出。

true