android - JSON and location distance calculate -

i planning this. first device location , info json. json includes latitude , longitude. after, calculate every items distance device. if less x number show in list view. have used use json parsing , list view basic.

and here code location calculate

location locationa = new     location("point a"); locationa.setlatitude(lata); locationa.setlongitude(lnga); location     locationb = new location("point b");  locationb.setlatitude(latb);  locationb.setlongitude(lngb);  float     distance = locationa.distanceto(locationb); 

i use code.

i think this. json items. before on list check distance if lover x put in list else return getting json item

i need codes it.

so have code calculate distance 2 points coordinates? make web page. can save coordinates database, when have phone position can take coordinates near position (like filter). after can use code check witch coordinates inside range x , put class contain coordinates.

your coordinates class:

public class coordinates {  private double _lat; private double _lng;   //empty constructor public coordinates(){  } //constructor public coordinates(int id, double lat, double lng){     this._lat = lat;     this._lng = lng; } // constructor public materia(double lat, double lng){     this._lat = lat;     this._lng = lng; } // getting id public int getid(){     return this._id; }  // setting id public void setid(int id){     this._id = id; }  //getting latitude public int getlat(){      return this._lat;  } //setting color public void setlat(double lat){      this._lat = lat;  } //getting longitude public double getlng() {      return this._lng;  } //setting longitude  public void setlng(double lng) {       this._lng = lng;   } } 

your database sqlite:

public class mysqlitehelper extends sqliteopenhelper {  //database version private static final int database_version = 1; //database name private static final string database_name = "coordinates.db"; //materie table name public static final string table_coordinates = "coordinates"; //coordinates columns table names public static final string column_id = "_id"; public static final string column_lat = "latitude"; public static final string column_lng = "longitude";  public mysqlitehelper(context context) {     super(context, database_name, null, database_version); } oncreate(){} onupdate(){} //other methods need  //here // getting coordinates public list<coordinate> getallcoordinate() {     list<coordinate> coordinatelist = new arraylist<coordinate>();     // select query     string selectquery = "select  * " + table_coordinates;      sqlitedatabase db = this.getwritabledatabase();     cursor cursor = db.rawquery(selectquery, null);      // looping through rows , adding list     if (cursor.movetofirst()) {         {             coordinate coordinate = new coordinate();             coordinate.setid(double.parsedouble(cursor.getstring(0)));             coordinate.setlat(double.parsedouble(cursor.getstring(1)));             coordinate.setlng(double.parsedouble(cursor.getstring(2)));             // adding contact list            coordinatelist.add(coordinate);         } while (cursor.movetonext());     }      // return coordinate list     return coordinatelist; } 

with getallcoordinate take coordinate in database , generate array of object can read , access single lat , lng. maybe code not perfect if use take care errors. here guide database