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.

Answer 1

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