Reading value of nested key in JSON with Java (Jackson) -

i'm new java programmer coming background in python. have weather data that's being collected/returned json nested keys in it, , don't understand how pull values out in situation. i'm sure question has been asked before, swear i've googled great deal , can't seem find answer. right i'm using json-simple, tried switching jackson , still couldn't figure out how this. since jackson/gson seem used libraries, i'd love see example using 1 of libraries. below sample of data, followed code i've written far.

{     "response": {         "features": {             "history": 1         }      },     "history": {         "date": {             "pretty": "april 13, 2010",             "year": "2010",             "mon": "04",             "mday": "13",             "hour": "12",             "min": "00",             "tzname": "america/los_angeles"         },         ...     } } 

main function

public class tester {      public static void main(string args[]) throws malformedurlexception, ioexception, parseexception {         wundergroundapi wu =  new wundergroundapi("*******60fedd095");          jsonobject json = wu.historical("san_francisco", "ca", "20100413");          system.out.println(json.tostring());         system.out.println();         //this returns 1 level. further .get() calls throw exception         system.out.println(json.get("history"));     } } 

the function 'historical' calls function returns jsonobject

public static jsonobject readjsonfromurl(url url) throws malformedurlexception, ioexception, parseexception {      inputstream inputstream = url.openstream();      try {         jsonparser parser = new jsonparser();         bufferedreader buffreader = new bufferedreader(new inputstreamreader(inputstream, charset.forname("utf-8")));          string jsontext = readall(buffreader);         jsonobject json = (jsonobject) parser.parse(jsontext);         return json;     } {         inputstream.close();     } } 

with jackson's tree model (jsonnode), have both "literal" accessor methods ('get'), returns null missing value, , "safe" accessors ('path'), allow traverse "missing" nodes. so, example:

jsonnode root = mapper.readtree(inputsource); int h = root.path("response").path("history").getvalueasint(); 

which return value @ given path, or, if path missing, 0 (default value)

but more conveniently, can use json pointer expression:

int h = root.at("/response/history").getvalueasint(); 

there other ways too, , more convenient model structure plain old java object (pojo). content fit like:

public class wrapper {   public response response; }  public class response {   public map<string,integer> features; // or maybe map<string,object>   public list<historyitem> history; } public class historyitem {   public mydate date; // or map<string,string>   // ... , forth } 

and if so, traverse resulting objects java objects.