How do we convert JSON to Map in Java

Question

Which is the best way to convert a JSON code as this:

{ ​
    "data" : 
    { 
        "field1" : "value1", 
        "field2" : "value2"
    }
}

in a Java Map in which one the keys are (field1, field2) and the values for those fields are (value1, value2).

Any ideas? Should I use Json-lib for that? 

Answer 1

For a simple mapping, most tools from http://json.org (section java) would work. 

HashMap<String,Object> results = new ObjectMapper().readValue(JSON_SOURCE, HashMap.class);

(where JSON_SOURCE is a File, input stream, reader, or json content String)

Hope it helps!

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Answer 2

When you don't know structure of json. You can use

JsonElement root = new JsonParser().parse(jsonString);

and then you can work with json. e.g. how to get "value1" from your gson:

String value1 = root.getAsJsonObject().get("data").getAsJsonObject().get("field1").getAsString();