如何在SpringMVC中为特定类自定义JSON

Question

I'm using SpringMVC and have the following Method.

@RequestMapping("/login")
public @ResponseBody User login(User user) {
    // some operation here ....
    return user;
}

In most cases, SpringMVC converts an object to JSON in a proper manner. However sometimes you might need to customize the JSON. Where can I customize the JSON for ALL the User object. I want the behavior of converting a User object to JSON to be consistent across the board. I guess a listener or interface can achieve that. Does that kind of solution exist?

PS. What if the Object I wanna convert is an instance of third-party class? I cannot customize it in the class definition because I don't have the source code...

Answer 1

Spring uses Jackson to serialize and deserialize JSON by default. You can use Jackson's @JsonSerialize annotation on your User type and provider a JsonSerializer implementation which performs the serialization as you want it.

Answer 2

Below posting an example for deserializing json Array to Arraylist

@RequestMapping(value = "/mapJsonObjects", method = RequestMethod.POST)
public static ModelAndView parseJSONObjects(@RequestParam String jsonList,HttpServletRequest request,
        HttpServletResponse response) throws Exception {
    JSONParser parser=new JSONParser();
    ArrayList filteredList = new ArrayList();
   Object obj = parser.parse(jsonList);
   JSONArray newList = (JSONArray)obj;
   filteredList = newList;
              -----------

}

To convert an array List to json array. First add the below beans to springServlet.xml

<bean name="jsonView"
    class="org.springframework.web.servlet.view.json.JsonView">
    <property name="contentType">
        <value>text/html</value>
    </property>
</bean>

Then from the controller return the arraylist as below

                Map<String, Object> filteredMap = new LinkedHashMap<String, Object>();
                List<Accountdb> filteredList;
                ------filteredMap logic -----------
            filteredAccountMap.put("rows", filteredList);
            return new ModelAndView("jsonView", filteredMap);