Java の話です。

Gson

Gson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Gson can work with arbitrary Java objects including pre-existing objects that you do not have source-code of.

Gson を使うと Java Object から JSON、又はその逆の変換をとても簡単に行うことができます。

Java Object to JSON

HogeParam hogeParam = new HogeParam();
hogeParam.setId(111);
hogeParam.setName("nyaruko");
hogeParam.setEntries(entrieList);
Gson gson = new Gson();
String jsonString = gson.toJson(hogeParam);

JSON to Java Object

HogeParam javaParam = gson.fromJson(jsonString, HogeParam.class);
Integer id = javaParam.getId();
String name = javaParam.getName();
for (Entry entry : javaParam.getEntries()) { }

みたいな感じに。 リストも入れ子もいけちゃいます。らくちんらくちん。