使用@RequestBody将请求体映射到Action方法参数中

    @PostMapping("/user")
    public User create(@RequestBody User user){
        System.out.println(user.toString());
        user.setId(5l);
        return user;
    }

    @Test
    public void whenCreateSuccess() throws Exception {
        String content = "{"username":"fanqi","password":"admin","enabled":"1"}";
        mockMvc.perform(MockMvcRequestBuilders.post("/user")
                .contentType(MediaType.APPLICATION_JSON_UTF8)
                .content(content))
                .andExpect(status().isOk())
                .andExpect(jsonPath("$.id").exists());
    }