Easymock 简明教程

EasyMock - Adding Behavior

EasyMock 使用方法 expect() 和 expectLassCall() 为模拟对象添加了功能。查看以下代码段。

//add the behavior of calc service to add two numbers
EasyMock.expect(calcService.add(10.0,20.0)).andReturn(30.00);

这里我们指示 EasyMock 对 calcService 的 add 方法的行为是添加 10 和 20，返回 30.00 的值。

在此时，Mock 只记录了行为，但它并未按预期作为模拟对象工作。调用 replay 后，它将按预期工作。

//add the behavior of calc service to add two numbers
EasyMock.expect(calcService.add(10.0,20.0)).andReturn(30.00);

//activate the mock
//EasyMock.replay(calcService);

Example without EasyMock.Replay()

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

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);
}

Step 2: Create a JAVA class to represent 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);
   }
}

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。

文件: MathApplicationTester.java

import org.easymock.EasyMock;
import org.easymock.EasyMockRunner;
import org.easymock.Mock;
import org.easymock.TestSubject;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

//@RunWith attaches a runner with the test class to initialize the test data
@RunWith(EasyMockRunner.class)
public class MathApplicationTester {
   // @TestSubject annotation is used to identify the class which is going to use the mock object
   @TestSubject
   MathApplication mathApplication = new MathApplication();

   //@Mock annotation is used to create the mock object to be injected
   @Mock
   CalculatorService calcService;

   @Test
   public void testAdd(){
      //add the behavior of calc service to add two numbers
      EasyMock.expect(calcService.add(10.0,20.0)).andReturn(30.00);

      //activate the mock
      //EasyMock.replay(calcService);

      //test the add functionality
      Assert.assertEquals(mathApplication.add(10.0, 20.0),30.0,0);
   }
}

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。

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());
   }
}

Step 5: Verify the Result

使用以下 javac 编译器编译类：

C:\EasyMock_WORKSPACE>javac Calculator Service.java Math Application.java Math Application Tester.java Test Runner.java

现在运行测试运行器以查看结果 −

C:\EasyMock_WORKSPACE>java TestRunner

Output

验证输出。

testAdd(MathApplicationTester): expected:<0.0> but was:<30.0>
false

Example with EasyMock.Replay()

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