如何轻松将POJO转换为JSON数据？

Question

How can I make this more reusable across our DAO objects?

List<User> list = userService.getAll();

JSONObject json = new JSONObject();
JSONArray jsonArray = new JSONArray();

for(User user : list) {
    JSONObject userJson = new JSONObject();
    userJson.put("id", user.getId());
    userJson.put("FirstName", user.getFirstName());
    ....
    jsonArray.add(userJson);
}

json.put("results", jsonArray);

return json.toJsonString();

Anyway, that's code from memory but you get the idea. There has to be an easier way. Also, we don't always want to return every property of the POJO. In some situations, we may only want the FirstName and LastName and in others, we would add PhoneNumber , etc.

Thanks for any suggestions.

Answer 1

I would use Google Gson
Very easy to use

Answer 2

You can also try Genson library http://code.google.com/p/genson/ .

It has full databinding support but also a low level streaming api. It is easy to use, according to users feedback it would be easier to use than Jackson. There are a couple of features that it is the only one to provide, such as deserialization to an object using its constructor with any additional annotations.

To get started you can have a look at the wiki http://code.google.com/p/genson/wiki/GettingStarted it should help to start quickly.