How To Convert KML File to GeoJson ?

If you want to convert KML file to GeoJson file, refer below mention library for such conversion

• library Name:osmbonuspack

• for installation refer following link :https://github.com/MKergall/osmbonuspack/wiki/HowToInclude
• for more reference follow this link: https://github.com/MKergall/osmbonuspack/wiki/Tutorial_4
• there are function name saveASKml,saveAsGeoJson use this function to convert the KMl file to GeoJson and vice versa 

Example:
In following example we are going use KML file from row folder and convert it in to GeoJson file and sore in SD Card.

 InputStream ins = getResources().openRawResource(  
 getResources().getIdentifier("pmc_election_ward_boundaries",  
 "raw", getPackageName()));  //take file from row folder
 kmlDocument = new KmlDocument();  
 kmlDocument.parseKMLStream(ins, null);  
 fCreated = kmlDocument.saveAsGeoJSON(new File(Environment.getExternalStorageDirectory() + "/sample.geojson"));  

Download Sample Code

Screenshot:

•  file name sample.geojson is converted from KML file to geoJosn 

•  GeoJson file plot on mapbox

Upgrade existing Database

When we want to add some new field in existing data base and Don't want to lose old data of user? What we have to do in such situation?
Solution: - While giving updates to android application , some time we are making some changes in database such as adding a new field but the main problem is that our application is live,so we need to take care of user's existing data which is stored in database. SQLite provides onUpgrade() method to overcome such situation. onUpgrade() is called when database version is changed which means that your database table structure having some changes. Just follow the following steps

• To add a new column into the existing table, fire "Alter" query in onUpgrade() method of SQLiteOpenHelper 
• Change version of database(you can not downgrade version of database)

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public class DBManager extends SQLiteOpenHelper { private SQLiteDatabase sqLiteDatabase; private int dbVersion = 2; //changed version private DBManager(Context context) { super(context,"DbSample", null, dbVersion); } }

      Remember one thing  onUpgrade() method is called only when version of database  is changed

• Now write alter query in onUpgrade()

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@Override public void onUpgrade(SQLiteDatabase sqLiteDatabase, int oldVersion, int newVersion) { if (newVersion > oldVersion) { sqLiteDatabase.execSQL("ALTER TABLE " + tbName + " ADD COLUMN roll INTEGER DEFAULT 0"); } }

• Download sample Code
• screenshot