java - Parsing JSON using GSON -

this continuation of previous question. after getting json request , turning json, trying parse result java object.

public class netclientget {    @suppresswarnings("unchecked")   public static void main(string[] args) {     string urlyesterday = "http://fids.changiairport.com/webfids/fidsp/get_flightinfo_cache.php?d=-1&type=pa&lang=en";     string yesterdayjson = getdatafromweb(urlyesterday);     //system.out.println("yesterdayjson : " + yesterdayjson);     //jsonarray.add(yesterdayjson);     gson gson = new gson();     list<flightinfo> flightarray = (list<flightinfo>) gson.fromjson(yesterdayjson, flightinfo.class);     system.out.println("flightarray : " + flightarray);   }    private static string getdatafromweb(string targeturl) {     try {       url url = new url(targeturl);       httpurlconnection conn = (httpurlconnection) url.openconnection();       conn.setrequestmethod("get");       conn.setrequestproperty("accept", "application/json");       if (conn.getresponsecode() != 200) {         throw new runtimeexception("failed : http error code : " + conn.getresponsecode());       }       bufferedreader br;       if ("gzip".equalsignorecase(conn.getcontentencoding())) {         br = new bufferedreader(new inputstreamreader(         (new gzipinputstream(conn.getinputstream()))));       } else {         br = new bufferedreader(new inputstreamreader(         (conn.getinputstream())));       }       // retrieve data server       string output = null;       final stringbuffer buffer = new stringbuffer(16384);       while ((output = br.readline()) != null) {         buffer.append(output);       }       conn.disconnect();       // extract json jsonp envelope       string jsonp = buffer.tostring();       string json = jsonp.substring(jsonp.indexof("(") + 1, //this index of callback envelope       jsonp.lastindexof(")"));       //system.out.println("output server");       //system.out.println(json);       return json;     } catch (malformedurlexception e) {       e.printstacktrace();     } catch (ioexception e) {       e.printstacktrace();     }     return null;   } } 

i tried:

gson gson = new gson(); flightinfo flightarray = gson.fromjson(yesterdayjson, flightinfo.class); 

but got me null, sure need parse list since data has lot of entries.

sample of json

"flights": [   {     "date": "2013-05-12",     "scheduled_time": "23:30",     "estimated_time": "23:09*",     "airline": "tr",     "flight_no": "tr2109",     "airport": "bkk",     "origin": "bangkok (suvarnabhumi)",     "via": "",     "terminal": "2",     "belt": "35",     "status": "landed",     "airline_name": "tiger airways",     "airline_alias": "",     "unixtime": "1368372600",     "master_flight_no": "tr2109",     "slave_flight_no": []   } ] 

and flightinfo.class

import java.sql.time; import java.util.date;  public class flightinfo {   private date date;   private time scheduled_time;   private time estimated_time;   private string airline;   private string flight_no;   private string airport;   private string origin;   private string via;   private string terminal;   private string belt;   private string status;   private string airline_name;    public date getdate() {     return date;   }   public void setdate(date date) {     this.date = date;   }   public time getscheduled_time() {     return scheduled_time;   }   public void setscheduled_time(time scheduled_time) {     this.scheduled_time = scheduled_time;   }   public time getestimated_time() {     return estimated_time;   }   public void setestimated_time(time estimated_time) {     this.estimated_time = estimated_time;   }   public string getairline() {     return airline;   }   public void setairline(string airline) {     this.airline = airline;   }   public string getflight_no() {     return flight_no;   }   public void setflight_no(string flight_no) {     this.flight_no = flight_no;   }   public string getairport() {     return airport;   }   public void setairport(string airport) {     this.airport = airport;   }   public string getorigin() {     return origin;   }   public void setorigin(string origin) {     this.origin = origin;   }   public string getvia() {     return via;   }   public void setvia(string via) {     this.via = via;   }   public string getterminal() {     return terminal;   }   public void setterminal(string terminal) {     this.terminal = terminal;   }   public string getbelt() {     return belt;   }   public void setbelt(string belt) {     this.belt = belt;   }   public string getstatus() {     return status;   }   public void setstatus(string status) {     this.status = status;   }   public string getairline_name() {     return airline_name;   }   public void setairline_name(string airline_name) {     this.airline_name = airline_name;   }   @override   public string tostring() {     return "flightinfo [date=" + date + ", scheduled_time=" + scheduled_time +       ", estimated_time=" + estimated_time +       ", airline=" + airline +       ", flight_no=" + flight_no +       ", airport=" + airport +       ", origin=" + origin +       ", via=" + via +       ", terminal=" + terminal +       ", belt=" + belt +       ", status=" + status +       ", airline_name=" + airline_name +       "]";   } } 

i assume json response surrounded { }, otherwise it's not valid json...

that said, need class parse json response, example:

public class response {         private list<flightinfo> flights;             //getters & setters } 

now can parse response with:

gson gson = new gson(); response response = gson.fromjson(yesterdayjson, response .class); list<flightinfo> flightarray = response.getflights(); 

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note: looking @ class flightinfo , json response, think you'll have trouble parsing date , time fields, suggest parse them strings , correct transformation... or you'll have create custom deserializer.