Convert java Object into Json String

Question

I have a java class Object:

class TempClass {
@Expose
String errorCode
@Expose
String message
String name
String cause

TempClass(String errorCode, String message) {
    this.errorCode = errorCode
    this.message = message
  }
}

I am able to convert object into json using GSON jar

TempClass t = new TempClass("404","page not found")
GsonBuilder builder = new GsonBuilder().excludeFieldsWithoutExposeAnnotation()
String json = builder.create().toJson(t);

The JSON String I am getting is

{ errorCode: "404", message: "page not found" }

But What I want is:

"TempClass"{ errorCode: "404", message: "page not found" }

Or Better if there is any other sophisticated way where I can map "tempClass" (or any other property) into something else.

Answer 1

You can try creating a Map, where "tempClass" is the key and your TempClass object is the value, like this:

TempClass t = new TempClass("404","page not found")
Map<String, Object> map = new Hashmap<String, Object> ();
map.put("tempClass", t);
GsonBuilder builder = new GsonBuilder().excludeFieldsWithoutExposeAnnotation()
String json = builder.create().toJson(map);

This is a sort of easy and fast way to achieve what you need due to Maps are parsed out-of-the-box by Gson, but be careful: in case you have more properties like this one, it could be better to create a new class for that