How to check String in response body with mockMvc

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 … Read more