createNiceMock（ createNiceMock）

EasyMock.createNiceMock（）创建一个mock并设置mock的每个方法的默认实现。 如果使用EasyMock.createMock（），则调用mock方法会抛出断言错误。

语法 (Syntax)

calcService = EasyMock.createNiceMock(CalculatorService.class);

例子 (Example)

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

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

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

让我们通过在其中注入一个模拟的calculatorService来测试MathApplication类。 Mock将由EasyMock创建。

这里我们通过expect（）添加了一个模拟方法调用add（）。 但是在测试期间，我们也调用了subtract（）和其他方法。 当我们使用EasyMock.createNiceMock（）创建模拟对象时，可以使用默认值的默认实现。

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.createNiceMock(CalculatorService.class);
      mathApplication.setCalculatorService(calcService);
   }
   @Test
   public void testCalcService(){
      //add the behavior to add numbers
      EasyMock.expect(calcService.add(20.0,10.0)).andReturn(30.0);
      //activate the mock
      EasyMock.replay(calcService);	
      //test the add functionality
      Assert.assertEquals(mathApplication.add(20.0, 10.0),30.0,0);
      //test the subtract functionality
      Assert.assertEquals(mathApplication.subtract(20.0, 10.0),0.0,0);
      //test the multiply functionality
      Assert.assertEquals(mathApplication.divide(20.0, 10.0),0.0,0);		
      //test the divide functionality
      Assert.assertEquals(mathApplication.multiply(20.0, 10.0),0.0,0);
      //verify call to calcService is made or not
      EasyMock.verify(calcService);
   }
}

Step 4: Execute test cases

在C:\》 EasyMock_WORKSPACE创建一个名为TestRunner的java类文件，以执行测试用例。

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javac编译器编译类，如下所示:

C:\EasyMock_WORKSPACE>javac MathApplicationTester.java

现在运行Test Runner来查看结果:

C:\EasyMock_WORKSPACE>java TestRunner

验证输出。

true