Convert JSON to Map

java json parsing collections

David Santamaria · Jan 14, 2009 · Viewed 490.3k times · Source

What 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? Or better if I write my own parser?

Answer

I hope you were joking about writing your own parser. :-)

For such a simple mapping, most tools from http://json.org (section java) would work. For one of them (Jackson https://github.com/FasterXML/jackson-databind/#5-minute-tutorial-streaming-parser-generator), you'd do:

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

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