How to deserialize JSON into flat, Map-like structure?

Question

Have in mind that the JSON structure is not known before hand i.e. it is completely arbitrary, we only know that it is JSON format.

For example,

The followin

Answer 1

how about that:

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import com.google.gson.Gson;

/**
 * NOT FOR CONCURENT USE
*/
@SuppressWarnings("unchecked")
public class JsonParser{

Gson gson=new Gson();
Map<String, String> flatmap = new HashMap<String, String>();

public Map<String, String> parse(String value) {        
    iterableCrawl("", null, (gson.fromJson(value, flatmap.getClass())).entrySet());     
    return flatmap; 
}

private <T> void iterableCrawl(String prefix, String suffix, Iterable<T> iterable) {
    int key = 0;
    for (T t : iterable) {
        if (suffix!=null)
            crawl(t, prefix+(key++)+suffix);
        else
            crawl(((Entry<String, Object>) t).getValue(), prefix+((Entry<String, Object>) t).getKey());
    }
}

private void crawl(Object object, String key) {
    if (object instanceof ArrayList)
        iterableCrawl(key+"[", "]", (ArrayList<Object>)object);
    else if (object instanceof Map)
        iterableCrawl(key+".", null, ((Map<String, Object>)object).entrySet());
    else
        flatmap.put(key, object.toString());
}
}