In this below application we had populated the listview's data and image from the sqlite
Here we are using a java class for creating the table
PlaceDataSQL.java
Here in the onCreate function the table is created, here for image we are using blog, so that we can insert the image inside the table itself and the onUpgrade function is used to upgrade the table on the next release, for example you had create an application and published it in market and a guy is using your application, now suddenly you like to add another field on your table means you need to change the " DATABASE_VERSION " to 2 and in the onUpgrade funtion you need to write the alter query there. Likewise i had using a funtion checkDataBase(), this is to check whether the database is exist or not.
Then in the main activity we are calling delete to delete the table content, likewise we will be using a function insertData, inside this function we will be inserting data to the table, like that we will be using getDataAndPopulate(), here we will be retrieving data from the table and displaying in the list.
The main thing is we inserting the image to database for this we are using HttpClient and on the retriving time it is very easy to assign the data, so while calling on the next time we can assign and there is no need of url call for showing image.
SqliteDBActivity.java
In this example i had wrote two types of retrieving methods from the table, by writing the query and specifying the table name itself.
Here we are using a java class for creating the table
PlaceDataSQL.java
package com.data.pack; package com.data.pack; import android.content.Context; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteException; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; /** Helper to the database, manages versions and creation */ public class PlaceDataSQL extends SQLiteOpenHelper { private static final String DATABASE_NAME = "sample.db"; private static final int DATABASE_VERSION = 1; private Context context; public PlaceDataSQL(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); this.context = context; } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("CREATE TABLE gallery (id varchar(20), image BLOB,caption varchar(160),description varchar(200))"); } private void versionUpdation(SQLiteDatabase db) { } /** * Check if the database already exist to avoid re-copying the file each * time you open the application. * * @return true if it exists, false if it doesn't */ public boolean checkDataBase(String db) { SQLiteDatabase checkDB = null; try { String myPath = "data/data/com.data.pack/databases/" + db; checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); } catch (SQLiteException e) { // database does't exist yet. } catch (Exception e) { } if (checkDB != null) { checkDB.close(); } return checkDB != null ? true : false; } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { if (oldVersion >= newVersion) return; if (oldVersion == 1) { Log.d("New Version", "Datas can be upgraded"); } Log.d("Sample Data", "onUpgrade : " + newVersion); } }
Here in the onCreate function the table is created, here for image we are using blog, so that we can insert the image inside the table itself and the onUpgrade function is used to upgrade the table on the next release, for example you had create an application and published it in market and a guy is using your application, now suddenly you like to add another field on your table means you need to change the " DATABASE_VERSION " to 2 and in the onUpgrade funtion you need to write the alter query there. Likewise i had using a funtion checkDataBase(), this is to check whether the database is exist or not.
Then in the main activity we are calling delete to delete the table content, likewise we will be using a function insertData, inside this function we will be inserting data to the table, like that we will be using getDataAndPopulate(), here we will be retrieving data from the table and displaying in the list.
The main thing is we inserting the image to database for this we are using HttpClient and on the retriving time it is very easy to assign the data, so while calling on the next time we can assign and there is no need of url call for showing image.
SqliteDBActivity.java
package com.data.pack; package com.data.pack; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.util.ArrayList; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.util.EntityUtils; import android.app.ListActivity; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Bundle; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.ImageView; import android.widget.TextView; public class SqliteDBActivity extends ListActivity { private static PlaceDataSQL placeData; private ArrayList id = new ArrayList(); private ArrayList image = new ArrayList(); private ArrayList caption = new ArrayList(); private ArrayList description = new ArrayList(); private Button populate; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); populate = (Button) findViewById(R.id.populate); placeData = new PlaceDataSQL(this); SQLiteDatabase db = placeData.getWritableDatabase(); Cursor cursors = getRawEvents("select * from gallery"); if (cursors.moveToNext()) { populate.setVisibility(View.GONE); getDataAndPopulate(); } else { populate.setVisibility(View.VISIBLE); } db.delete("gallery", "id=?", new String[] { "12" }); populate.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { try { callInsertion("1","https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiedFOs4rP2-GzeSBabJis7P6IhtP-DyX3ucrU3T8zkMgZD1HdJ8DegYyw3hj5vcqFzHsXr9i8MtTb8YIxRLLiV4uDWdarv_bpLLjApo6QvLmkpCdBsUwAThcTCu7qooNFpOX5vy8LHfD0/s1600/twitter_follow.gif","First","This is the first item"); callInsertion("2","https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhA8VvSfGPODnoPsPR03Mmk9Mx7kFSDdbZ4TypprJPPI-_14TeQ9dD78mSbUdtMVnq1QSTRfYmdAlITaSeEEbYdvd6A8GKfzCmAAFekwBtgC2Fk1q1cOVFdDrp-8eVMnwdSSP6Fx8qjUQ0/s320/seek.JPG","Second","This is the second item"); } catch (ClientProtocolException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } getDataAndPopulate(); } }); } private void callInsertion(String id, String url, String caption, String description) throws ClientProtocolException, IOException { DefaultHttpClient mHttpClient = new DefaultHttpClient(); HttpGet mHttpGet = new HttpGet(url); HttpResponse mHttpResponse = mHttpClient.execute(mHttpGet); if (mHttpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) { HttpEntity entity = mHttpResponse.getEntity(); if ( entity != null) { // insert to database insertData(id,EntityUtils.toByteArray(entity),caption,description); } } } private void insertData(String id, byte[] image, String caption, String description) { SQLiteDatabase db = placeData.getWritableDatabase(); ContentValues values; values = new ContentValues(); values.put("id", id); values.put("image", image); values.put("caption", caption); values.put("description", description); db.insert("gallery", null, values); } private void getDataAndPopulate() { id = new ArrayList(); image = new ArrayList(); caption = new ArrayList(); description = new ArrayList(); Cursor cursor = getEvents("gallery"); while (cursor.moveToNext()) { String temp_id = cursor.getString(0); byte[] temp_image = cursor.getBlob(1); String temp_caption = cursor.getString(2); String temp_description = cursor.getString(3); id.add(temp_id); image.add(temp_image); caption.add(temp_caption); description.add(temp_description); } String[] captionArray = (String[]) caption.toArray( new String[caption.size()]); ItemsAdapter itemsAdapter = new ItemsAdapter( SqliteDBActivity.this, R.layout.item, captionArray); setListAdapter(itemsAdapter); populate.setVisibility(View.GONE); } private class ItemsAdapter extends BaseAdapter { String[] items; public ItemsAdapter(Context context, int textViewResourceId, String[] items) { this.items = items; } @Override public View getView(final int POSITION, View convertView, ViewGroup parent) { TextView desc; TextView cap; View view = convertView; ImageView img; if (view == null) { LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); view = vi.inflate(R.layout.item, null); } img = (ImageView) view.findViewById(R.id.image); cap = (TextView) view.findViewById(R.id.caption); desc = (TextView) view.findViewById(R.id.description); cap.setText(caption.get(POSITION)); desc.setText(description.get(POSITION)); img.setImageBitmap(BitmapFactory.decodeByteArray(image.get(POSITION), 0, image.get(POSITION).length)); return view; } public int getCount() { return items.length; } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } } private Cursor getRawEvents(String sql) { SQLiteDatabase db = (placeData).getReadableDatabase(); Cursor cursor = db.rawQuery(sql, null); startManagingCursor(cursor); return cursor; } private Cursor getEvents(String table) { SQLiteDatabase db = (placeData).getReadableDatabase(); Cursor cursor = db.query(table, null, null, null, null, null, null); startManagingCursor(cursor); return cursor; } }
In this example i had wrote two types of retrieving methods from the table, by writing the query and specifying the table name itself.
nice friend very nice blog
ReplyDelete