玩转单元测试之Testing Spring MVC Controllers

玩转单元测试之 Testing Spring MVC Controllers

转载注明出处：http://www.cnblogs.com/wade-xu/p/4311657.html

The Spring MVC Test framework provides first class JUnit support for testing client and server-side Spring MVC code through a fluent API. Typically it loads the actual Spring configuration through theTestContext framework and always uses the DispatcherServlet to process requests thus approximating full integration tests without requiring a running Servlet container.

Spring MVC 测试框架本来是一个独立的项目，由于发展的很好，早已合并到Spring Framework 3.2 里了，测试框架提供了很好的API来测试客户端和服务端的Spring MVC代码， 本文以两个例子讲述了服务端的测试，闲话少说，让我们边看例子边学习。

目录
  Getting Ready
  Example
     Reference Class
     Unit Test
     Integration Testing
     总结
  Troubleshooting
  参考

Getting Ready

测试相关Maven dependency如下:

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>4.0.3.RELEASE</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.mockito</groupId>
        <artifactId>mockito-all</artifactId>
        <version>1.9.5</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
        <scope>test</scope>
    </dependency>

<dependency>
          <groupId>org.hamcrest</groupId>
          <artifactId>hamcrest-core</artifactId>
          <version>1.3</version>
          <scope>test</scope>
      </dependency>

关于Spring项目的一些依赖如（spring-context, spring-web, spring-webmvc, spring-beans），这里就不列举了

Example

Reference Class

Controller 如下：

@Controller
@RequestMapping("/")
public class DemoController {

    @Autowired
    private TestProjectService testProjectService;

    @RequestMapping(value = "jsonCompare", method = RequestMethod.POST)
    @ResponseBody
    public List<FieldComparisonFailure> jsonCompare(@RequestParam("expect") String expect, @RequestParam("actual") String actual, ModelMap model,
            HttpSession session) {

        List<FieldComparisonFailure> list = testProjectService.compare(expect, actual);

        return list;
    }

}

FieldComparisonFailure类如下

/**
 * Models a failure when comparing two fields.
 */
public class FieldComparisonFailure {
    private final String field;
    private final Object expected;
    private final Object actual;

    public FieldComparisonFailure(String field, Object expected, Object actual) {
        this.field = field;
        this.expected = expected;
        this.actual = actual;
    }

    public String getField() {
        return field;
    }

    public Object getExpected() {
        return expected;
    }

    public Object getActual() {
        return actual;
    }
}

TestProjectService接口如下：

public interface TestProjectService {
    public List<FieldComparisonFailure> compare(String expect, String actual);

}

TestProjectServiceImpl 具体实现是比较两个Json字符串 返回一个List

@Service
public class TestProjectServiceImpl implements TestProjectService {

    @Override
    public List<FieldComparisonFailure> compare(String expect, String actual) {

        Comparator comparator = new Comparator();
        List<FieldComparisonFailure> list = new ArrayList<FieldComparisonFailure>();

        try {
            list = comparator.compare(expect, actual);
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return list;
    }

}

##转载注明出处：http://www.cnblogs.com/wade-xu/p/4311657.html

Unit Test

首先来看一个独立的单元测试方式， 这个例子用Mockito 模拟service层以便隔离controller的测试。

package com.wadeshop.controller;

import static org.mockito.Mockito.when;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.hamcrest.Matchers.hasSize;

import org.junit.Before;
import org.junit.Test;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;

import com.google.common.collect.ImmutableList;
import com.wadeshop.service.TestProjectService;
import com.wadeshop.entity.FieldComparisonFailure;

public class DemoControllerTest_mock {

    @Mock
    private TestProjectService testProjectService;

    @InjectMocks
    private DemoController demoController;

    private MockMvc mockMvc;

    @Before
    public void setup() {

        // initialize mock object
        MockitoAnnotations.initMocks(this);

        // Setup Spring test in standalone mode
        this.mockMvc = MockMvcBuilders.standaloneSetup(demoController).build();
    }

    @Test
    public void test() throws Exception {

        //prepare test data
        FieldComparisonFailure e1 = new FieldComparisonFailure("Number", "3", "4");
        FieldComparisonFailure e2 = new FieldComparisonFailure("Number", "1", "2");

        //actually parameter haven't use, service was mocked
        String expect = "";
        String actual = "";

        //Sets a return value to be returned when the method is called
        when(testProjectService.compare(expect, actual)).thenReturn(ImmutableList.of(e1, e2));

        //construct http request and expect response
       this.mockMvc
            .perform(post("/jsonCompare")
                     .accept(MediaType.APPLICATION_JSON)
               .param("actual", actual)
               .param("expect", expect))
               .andDo(print()) //print request and response to Console
               .andExpect(status().isOk())
               .andExpect(content().contentType("application/json;charset=UTF-8"))
               .andExpect(jsonPath("$", hasSize(2)))
               .andExpect(jsonPath("$[0].field").value("Number"))
               .andExpect(jsonPath("$[0].expected").value("3"))
               .andExpect(jsonPath("$[0].actual").value("4"))
               .andExpect(jsonPath("$[1].field").value("Number"))
               .andExpect(jsonPath("$[1].expected").value("1"))
               .andExpect(jsonPath("$[1].actual").value("2"));

         //verify Interactions with any mock
         verify(testProjectService, times(1)).compare(expect, actual);
         verifyNoMoreInteractions(testProjectService);
    }
}

@Mock: 需要被Mock的对象

@InjectMocks: 需要将Mock对象注入的对象, 此处就是Controller

Before test

初始化Mock对象， 通过MockMvcBuilders.standaloneSetup模拟一个Mvc测试环境，注入controller, 通过build得到一个MockMvc， 后面就用MockMvc的一些API做测试。

这不是真实的Spring MVC环境，如果要模拟真实环境需要用 MockMvcBuilders.webAppContextSetup(webApplicationContext).build()， 见下文。

测试方法里面需要构建测试数据，mock service调用方法，返回一个ImmutableList （google-collections 谷歌的集合库）

然后构造http请求并且传入参数执行， 最后断言验证期望结果， 关于JsonPath的使用请参考http://goessner.net/articles/JsonPath/

运行

andDo(print()) 打印到控制台的信息如下

MockHttpServletRequest:
         HTTP Method = POST
         Request URI = /jsonCompare
          Parameters = {actual=[], expect=[]}
             Headers = {Accept=[application/json]}

             Handler:
                Type = com.wadeshop.controller.DemoController

               Async:
   Was async started = false
        Async result = null

  Resolved Exception:
                Type = null

        ModelAndView:
           View name = null
                View = null
               Model = null

            FlashMap:

MockHttpServletResponse:
              Status = 200
       Error message = null
             Headers = {Content-Type=[application/json;charset=UTF-8]}
        Content type = application/json;charset=UTF-8
                Body = [{"field":"Number","actual":"4","expected":"3"},{"field":"Number","actual":"2","expected":"1"}]
       Forwarded URL = null
      Redirected URL = null
             Cookies = []

##转载注明出处：http://www.cnblogs.com/wade-xu/p/4311657.html

Integration Testing

再来看集成Web环境方式， 这次仍然使用Spring MVC Test 但还需要加载 WebApplicationContext

import static org.hamcrest.Matchers.hasSize;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration(value = "src/main/webapp")
@ContextConfiguration("file:src/main/resources/applicationContext.xml")

public class DemoControllerTest {

    @Autowired
    private WebApplicationContext wac;
    private MockMvc mockMvc;

    @Before
    public void setUp() {
        mockMvc = MockMvcBuilders.webAppContextSetup(wac).build();
    }

    @Test
    public void test() throws Exception {
        String actual = "{\"orderNumber\": \"4955\",\"orderVersion\": \"1\"}";
        String expect = "{\"orderNumber\": \"4956\",\"orderVersion\": \"1\"}";

       this.mockMvc
            .perform(post("/jsonCompare")
                     .accept(MediaType.APPLICATION_JSON)
               .param("actual", actual)
               .param("expect", expect))
               .andDo(print())
               .andExpect(status().isOk())
               .andExpect(content().contentType("application/json"))
               .andExpect(jsonPath("$", hasSize(1)))
               .andExpect(jsonPath("$[0].field").value("orderNumber"))
               .andExpect(jsonPath("$[0].actual").value("4955"))
               .andExpect(jsonPath("$[0].expected").value("4956"));
    }
}

@RunWith: 告诉Junit使用 Spring-Test 框架, 允许加载web 应用程序上下文。

@WebAppConfiguration: 表明该类会使用web应用程序的默认根目录来载入ApplicationContext, value = "src/main/webapp" 可以不填，默认此目录

@ContextConfiguration： 指定需要加载的spring配置文件的地址 ("file:src/main/resources/applicationContext.xml")

@Autowired WebApplicationContext wac：注入web环境的ApplicationContext容器；

使用MockMvcBuilders.webAppContextSetup(wac).build()来创建一个MockMvc进行测试, 此为模拟真实的Spring MVC环境

测试过程和前面一个例子大体相似，唯一的区别就是，这次传入的是真实的参数，调用真实的service取得返回值。

运行时间比较长

控制台信息

MockHttpServletRequest:
         HTTP Method = POST
         Request URI = /jsonCompare
          Parameters = {actual=[{"orderNumber": "4955","orderVersion": "1"}], expect=[{"orderNumber": "4956","orderVersion": "1"}]}
             Headers = {Accept=[application/json]}

             Handler:
                Type = com.wadeshop.controller.DemoController

               Async:
   Was async started = false
        Async result = null

  Resolved Exception:
                Type = null

        ModelAndView:
           View name = null
                View = null
               Model = null

            FlashMap:

MockHttpServletResponse:
              Status = 200
       Error message = null
             Headers = {Content-Type=[application/json]}
        Content type = application/json
                Body = [{"field":"orderNumber","actual":"4955","expected":"4956"}]
       Forwarded URL = null
      Redirected URL = null
             Cookies = []

从上面的例子来看集成测试Spring MVC controller是不是也很简单， 稍微配置一下就行了。

##转载注明出处：http://www.cnblogs.com/wade-xu/p/4311657.html

总结

单元测试过程无非就这三部曲：

1. 准备 （测试环境，测试数据）
2. 执行 （构造请求传入参数执行）
3. 断言 （验证结果）

Troubleshooting

如果发现一些NoClassDefFoundError， 估计依赖的jar版本太旧了。

import 哪些类不要弄错了，有些需要static import, IDE工具不一定会提示导入

参考

官方文档：http://docs.spring.io/spring/docs/4.0.0.RELEASE/spring-framework-reference/htmlsingle/#spring-mvc-test-framework

MVC测试框架更多的API请参考这篇博客：http://jinnianshilongnian.iteye.com/blog/2004660

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##转载注明出处： http://www.cnblogs.com/wade-xu/p/4299710.html