Junit--EasyMock测试servlet

用EasyMock做单元测试

import com.wang.service.service.Service;
import org.easymock.EasyMock;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import static org.junit.Assert.assertNotNull;

/**
 * UserRegister Tester.
 *
 * @author <Authors name>
 * @version 1.0
 * @since <pre>六月 16, 2018</pre>
 */
public class UserRegisterTest {


    private HttpServletRequest request;
    private HttpServletResponse response;
    private HttpSession session;

    @Before
    public void before() throws Exception {
        // 创建request和response的Mock
        request = EasyMock.createMock(HttpServletRequest.class);
        response = EasyMock.createMock(HttpServletResponse.class);
        session = EasyMock.createMock(HttpSession.class);
    }

    @After
    public void after() throws Exception {
    }

    /**
     * Method: newService()
     */
    @Test
    public void testNewService() throws Exception {
//TODO: Test goes here... 
    }

    /**
     * Method: execute(HttpServletRequest req, HttpServletResponse resp)
     */
    @Test
    public void testExecute() throws Exception {
        Service service = UserRegister.newService();

        EasyMock.expect(request.getParameter("rUserName")).andReturn("UserRegisterTest").once();    //期望使用参数
        EasyMock.expect(request.getParameter("rUserPassword1")).andReturn("testtest").times(1);  //期望调用的次数

        EasyMock.replay(request);   //保存期望结果

        ServiceResult result = service.execute(request, response);

        assertNotNull(result.getPage());
        assertNotNull(result.getErrormsg());
    }

}

EasyMock

引入到工程

使用如下方式在Maven中添加EasyMock的依赖：

<dependency>  
    <groupId>org.easymock</groupId>  
    <artifactId>easymock</artifactId>  
    <version>3.4</version>  
    <scope>test</scope>  
</dependency>

基本用法

先“录制”后使用：
- 先创建一个mock对象： EasyMock.createMock
- 录制对象的行为（打桩）
- 声明录制完成：EasyMock.replay

UserDao mock  = EasyMock.createMock(UserDao.class);//创建Mock对象 
            EasyMock.expect(mock.getById("1001")).andReturn(expectedUser);//录制Mock对象预期行为 
EasyMock.expect(mock.getById("1002")).andThrow(new RuntimeException());

EasyMock.replay(mock);//重放Mock对象，测试时以录制的对象预期行为代替真实对象的行为

高级用法

参数匹配

匹配特定参数

EasyMock.expect(mock.getById("1001")).andThrow(new RuntimeException());

匹配参数类型

EasyMock.expect(mock.getById(EasyMock.isA(String.class))).andReturn(exceptedUser).times(3);

isA()方***使用instanceof进行参数类型匹配，类似的方法还有anyInt()，anyObject()，
isNull()，same(), startsWith()……

mock void方法

mock.updateUserById(“TestId”);    
EasyMock.expectLastCall().anytimes(); 
//EasyMock.expectLastCall().andThrow(new RuntimeException()).anytimes();

多次调用返回不同值

EasyMock.expect(rs.next()).andReturn(true).times(2).andReturn(false).times(1);

PowerMock双剑合璧

Why：如果遇到了静态、final类型的类和方法，以及私有方法，EasyMock的动态代理局限性使得无法测试这些特性情况。
How：用了字节码操作技术直接对生成的字节码类文件进行修改，从而可以方便对静态，final类型的类和方法进行Mock，还可以对私有方法进行Mock，更可以对类进行部分Mock。

引入到工程

<properties>
    <powermock.version>1.6.6</powermock.version>
</properties>

<dependencies>
    <dependency>    
      <groupId>org.powermock</groupId>    
      <artifactId>powermock-api-easymock</artifactId>    
      <version>${powermock.version}</version>    
      <scope>test</scope>    
    </dependency>    
    <dependency>    
      <groupId>org.powermock</groupId>    
      <artifactId>powermock-module-junit4</artifactId>    
      <version>${powermock.version}</version>    
      <scope>test</scope>    
    </dependency>
</dependencies>

基本用法

先“声明”，再“录制”，后使用
- 声明powermock：当前测试类增加注解 @RunWith(PowerMockRunner.class)
- 声明需要操作字节码的类 @PrepareForTest({clzz1.class, clzz2.class})
- 录制对象的行为（打桩）
- 声明录制完成：PowerMock.replayAll

final类的静态方法

@RunWith(PowerMockRunner.class)
public class SystemPropertyMockDemoTest {
            
    @Test        
    public void demoOfFinalSystemClassMocking() throws Exception {         
        PowerMock.mockStatic(System.class);         
        PowerMock.when(System.getProperty("property")).thenReturn("my property");         
        PowerMock.replayAll();
     //enjoy your mock
    }
}

对于JDK的类如果要进行静态或final方法Mock时，不需要放在@PrepareForTest里面

@PrepareForTest({……})
注解既可以加在类层次上(对整个测试文件有效)，也可以加在测试方法上(只对测试方法有效)。

Mock部分方法或私有方法Mock

@RunWith(PowerMockRunner.class)     
@PrepareForTest(DataService.class)    
public class DataServiceTest {
       
    @Test    
    public void testReplaceData() throws Exception {    
        DataService tested = PowerMock.createPartialMock(DataService.class, "modifyData");//创建部分mock对象，只对modifyData方法Mock 
        PowerMock.expectPrivate(tested, "modifyData", "id", null).andReturn(true);//录制私有方法 
        PowerMock.replay(tested);    
        assertTrue(tested.deleteData(“id”));    
        PowerMock.verify(tested);    
    }    
}

带构造函数的mock

File fileMock = PowerMock.createMockAndExpectNew(File.class, "directoryPath");

import com.wang.service.service.Service;
import org.easymock.EasyMock;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import static org.junit.Assert.assertNotNull;

/**
 * UserRegister Tester.
 *
 * @author <Authors name>
 * @version 1.0
 * @since <pre>六月 16, 2018</pre>
 */
public class UserRegisterTest {


    private HttpServletRequest request;
    private HttpServletResponse response;
    private HttpSession session;

    @Before
    public void before() throws Exception {
        // 创建request和response的Mock
        request = EasyMock.createMock(HttpServletRequest.class);
        response = EasyMock.createMock(HttpServletResponse.class);
        session = EasyMock.createMock(HttpSession.class);
    }

    @After
    public void after() throws Exception {
    }

    /**
     * Method: newService()
     */
    @Test
    public void testNewService() throws Exception {
//TODO: Test goes here... 
    }

    /**
     * Method: execute(HttpServletRequest req, HttpServletResponse resp)
     */
    @Test
    public void testExecute() throws Exception {
        Service service = UserRegister.newService();

        EasyMock.expect(request.getParameter("rUserName")).andReturn("UserRegisterTest").once();    //期望使用参数
        EasyMock.expect(request.getParameter("rUserPassword1")).andReturn("testtest").times(1);  //期望调用的次数

        EasyMock.replay(request);   //保存期望结果

        ServiceResult result = service.execute(request, response);

        assertNotNull(result.getPage());
        assertNotNull(result.getErrormsg());
    }

}