How to check String in response body with mockMvc

Question

I have simple integration test    Test public void shouldReturnErrorMessageToAdminWhenCreatingUserWithUsedUserName   throws Exception       mockMvc perform post   api users   header  Authorization   base64ForTestUser  contentType MediaType APPLICATION JSON           content     userName     testUserDetails     firstName     xxx     lastName     xxx     password     xxx                andDo print             andExpect status   isBadRequest             andExpect         In last line I want to compare string received in response body to expected string  And in response I get   MockHttpServletResponse            Status   400    Error message   null          Headers    Content-Type  application json       Content type   application json             Body    Username already taken     Forwarded URL   null   Redirected URL   null   Tried some tricks with content    body   but nothing worked

User · Answer

Spring MockMvc now has direct support for JSON. So you just say:

.andExpect(content().json("{'message':'ok'}"));

and unlike string comparison, it will say something like "missing field xyz" or "message Expected 'ok' got 'nok'.

This method was introduced in Spring 4.1.

User · Answer

One possible approach is to simply include gson dependency   lt dependency gt       lt groupId gt com google code gson lt  groupId gt       lt artifactId gt gson lt  artifactId gt   lt  dependency gt   and parse the value to make your verifications   RunWith SpringRunner class   WebMvcTest HelloController class  public class HelloControllerTest         Autowired     private MockMvc mockMvc        MockBean     private HelloService helloService        Before     public void before             Mockito when helloService message    thenReturn  quot hello world  quot                Test     public void testMessage   throws Exception           MvcResult mvcResult   mockMvc perform MockMvcRequestBuilders get  quot   quot                     andExpect status   isOk                     andExpect content   contentTypeCompatibleWith MediaType APPLICATION JSON VALUE                    andReturn             String responseBody   mvcResult getResponse   getContentAsString            ResponseDto responseDto                   new Gson   fromJson responseBody  ResponseDto class           Assertions assertThat responseDto message  isEqualTo  quot hello world  quot

User · Answer

Here is an example how to parse JSON response and even how to send a request with a bean in JSON form     Autowired   protected MockMvc mvc     private static final ObjectMapper MAPPER   new ObjectMapper        configure SerializationFeature WRITE DATES AS TIMESTAMPS  false       configure DeserializationFeature FAIL ON UNKNOWN PROPERTIES  false       registerModule new JavaTimeModule        public static String requestBody Object request        try         return MAPPER writeValueAsString request         catch  JsonProcessingException e          throw new RuntimeException e                public static  lt T gt  T parseResponse MvcResult result  Class lt T gt  responseClass        try         String contentAsString   result getResponse   getContentAsString          return MAPPER readValue contentAsString  responseClass         catch  IOException e          throw new RuntimeException e                 Test   public void testUpdate         Book book   new Book        book setTitle  quot 1984 quot        book setAuthor  quot Orwell quot        MvcResult requestResult   mvc perform post  quot http   example com book  quot          contentType MediaType APPLICATION JSON         content requestBody book           andExpect status   isOk           andReturn        UpdateBookResponse updateBookResponse   parseResponse requestResult  UpdateBookResponse class       assertEquals  quot 1984 quot   updateBookResponse getTitle         assertEquals  quot Orwell quot   updateBookResponse getAuthor          As you can see here the Book is a request DTO and the UpdateBookResponse is a response object parsed from JSON  You may want to change the Jackson s ObjectMapper configuration

User · Answer

Another option is  when   def response   mockMvc perform              get   path to api                header  quot Content-Type quot    quot application json quot     then   response andExpect status   isOk    response andReturn   getResponse   getContentAsString       quot what you expect quot

User · Answer

You can call andReturn   and use the returned MvcResult object to get the content as a String   See below   MvcResult result   mockMvc perform post   api users   header  Authorization   base64ForTestUser  contentType MediaType APPLICATION JSON               content     userName     testUserDetails     firstName     xxx     lastName     xxx     password     xxx                    andDo MockMvcResultHandlers print                 andExpect status   isBadRequest                 andReturn     String content   result getResponse   getContentAsString       do what you will

User · Answer

Reading these answers  I can see a lot relating to Spring version 4 x  I am using version 3 2 0 for various reasons  So things like json support straight from the content   is not possible   I found that using MockMvcResultMatchers jsonPath is really easy and works a treat  Here is an example testing a post method   The bonus with this solution is that you re still matching on attributes  not relying on full json string comparisons    Using org springframework test web servlet result MockMvcResultMatchers   String expectedData    some value   mockMvc perform post   endPoint                    contentType MediaType APPLICATION JSON                   content mockRequestBodyAsString getBytes                      andExpect status   isOk                     andExpect MockMvcResultMatchers jsonPath    data   value expectedData      The request body was just a json string  which you can easily load from a real json mock data file if you wanted  but I didnt include that here as it would have deviated from the question   The actual json returned would have looked like this          data   some value

User · Answer

here a more elegant way  mockMvc perform post   retrieve page 1 amp countReg 999999                header  Authorization    Bearer     validToken                andExpect status   isOk                 andExpect content   string containsString  regCount

User · Answer

String body   mockMvc perform bla    bla  andReturn   getResolvedException   getMessage     This should give you the body of the response   Username already taken  in your case

User · Answer

Taken from spring s tutorial  mockMvc perform get       userName     bookmarks          this bookmarkList get 0  getId          andExpect status   isOk         andExpect content   contentType contentType        andExpect jsonPath    id   is this bookmarkList get 0  getId   intValue           andExpect jsonPath    uri   is  http   bookmark com 1     userName         andExpect jsonPath    description   is  A description        is is available from import static org hamcrest Matchers     jsonPath is available from import static org springframework test web servlet result MockMvcResultMatchers jsonPath   and jsonPath reference can be found here

User · Answer

You can use getContentAsString method to get the response data as string      String payload    quot      quot       String apiToTest    quot      quot            MvcResult mvcResult   mockMvc                  perform post apiToTest                   content payload                   contentType MediaType APPLICATION JSON                    andReturn             String responseData   mvcResult getResponse   getContentAsString     You can refer this link for test application

User · Answer

Spring security s  WithMockUser and hamcrest s containsString matcher makes for a simple and elegant solution    Test  WithMockUser roles    USER   public void loginWithRoleUserThenExpectUserSpecificContent   throws Exception       mockMvc perform get   index                 andExpect status   isOk                 andExpect content   string containsString  This content is only shown to users           More examples on github

User · Answer

Sotirios Delimanolis answer do the job however I was looking for comparing strings within this mockMvc assertion  So here it is    andExpect content   string    Username already taken - please try with different username         Of course my assertion fail   java lang AssertionError  Response content expected   lt  Username already taken - please try with different username  gt  but was  lt  Something gone wrong  gt    because     MockHttpServletResponse              Body    Something gone wrong    So this is proof that it works

[java] How to check String in response body with mockMvc

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