Easymock 简明教程

EasyMock - createMock

到目前为止，我们使用注解创建了模拟。EasyMock 提供了多种方法来创建模拟对象。EasyMock.createMock() 创建模拟而不必关心模拟在执行其动作时将要进行的方法调用的顺序。

So far, we’ve used annotations to create mocks. EasyMock provides various methods to create mock objects. EasyMock.createMock() creates mocks without bothering about the order of method calls that the mock is going to make in due course of its action.

Syntax

calcService = EasyMock.createMock(CalculatorService.class);

Example

Step 1: Create an interface called CalculatorService to provide mathematical functions

文件: CalculatorService.java

File: 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);
}

Step 2: Create a JAVA class to represent MathApplication

文件: MathApplication.java

File: 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);
   }
}

Step 3: Test the MathApplication class

让我们测试 MathApplication 类，并注入一个 calculatorService 模拟。模拟将由 EasyMock 创建。

Let’s test the MathApplication class, by injecting in it a mock of calculatorService. Mock will be created by EasyMock.

这里我们通过 expect() 向 mock 对象添加了两个模拟方法调用，add() 和 subtract()。然而，在测试期间，我们在调用 add() 之前调用了 subtract()。当我们使用 EasyMock.createMock() 创建模拟对象时，方法执行顺序无关紧要。

Here we’ve added two mock method calls, add() and subtract(), to the mock object via expect(). However during testing, we’ve called subtract() before calling add(). When we create a mock object using EasyMock.createMock(), the order of execution of the method does not matter.

文件: MathApplicationTester.java

File: 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);
   }
}

Step 4: Execute test cases

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

Create a java class file named TestRunner in C:\> EasyMock_WORKSPACE to execute Test case(s).

文件: TestRunner.java

File: 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());
   }
}

Step 5: Verify the Result

使用以下 javac 编译器编译类：

Compile the classes using javac compiler as follows −

C:\EasyMock_WORKSPACE>javac MathApplicationTester.java

现在运行测试运行器以查看结果 −

Now run the Test Runner to see the result −

C:\EasyMock_WORKSPACE>java TestRunner

Output

验证输出。

Verify the output.

true