Android Basic SQLite Tutorial for beginers

If you are just a  bigenner of Android app developer, after some basic apps you'll need to store your data in database like user name and password, high score of the game or much more. Android provides a simple and lite as name SQLite database to manage the Database.

What is SQLite

SQLite is a relational database (RDBMS). what makes SQLite unique is that it is considered as embedded solution. Most database management system such as Oracle, MySQL, and SQL Server are standalone server processes that run independently.

SQLite is actually a library that is linked into applications. All database operations are handled within the application through calls and functions contained in the SQLite library.

I am going to show you how to insert,update and delete data in SQLite.

create a new Project in your eclipse called UserDetail

Some Snapes of App
Home page screen shot

New Form Screen shot

// MainActivity.java

package com.example.userdetail;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
   
    Button newForm,toServer,editmode,delete_db;
    DataBaseHelper dbHelper;
    SQLiteDatabase mDB;
    Cursor mcur;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       
        dbHelper = new DataBaseHelper(this);
       
        newForm = (Button)findViewById(R.id.nform);
        toServer = (Button)findViewById(R.id.sendtoserver);
        editmode = (Button)findViewById(R.id.edit);
        delete_db = (Button)findViewById(R.id.delete_db);
       
        delete_db.setOnClickListener(new View.OnClickListener() {
           
            @Override
            public void onClick(View v) {
                try {
                    // Delete DataBase
                    mDB = dbHelper.getWritableDatabase();
                    mDB.execSQL("DROP TABLE "+DataBaseHelper.USER_TABLE);
                    dbHelper.onCreate(mDB);
                   
                } catch (Exception e) {
                    e.printStackTrace();
                }
               
            }
        });
       
        editmode.setOnClickListener(new View.OnClickListener() {
           
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this,DataList.class);
                startActivity(intent);
            }
        });
       
        newForm.setOnClickListener(new View.OnClickListener() {
           
            @Override
            public void onClick(View arg0) {
                Intent form = new Intent(getApplicationContext(),NewForm.class);
                form.putExtra("update", false);
                startActivity(form);
               
            }
        });
       
        toServer.setOnClickListener(new View.OnClickListener() {
           
            @Override
            public void onClick(View v) {
                          
                dbHelper = new DataBaseHelper(MainActivity.this);
                mDB = dbHelper.getReadableDatabase();
               
                String getData = "SELECT "+DataBaseHelper.NAME+","+DataBaseHelper.GENDER+","+DataBaseHelper.AGE+
                        " From "+DataBaseHelper.USER_TABLE;
                mcur = mDB.rawQuery(getData, null);
                int totalData = mcur.getCount();
                mcur.moveToFirst();
                for(int i=0;i<totalData;i++){
                   
                    String name = mcur.getString(0);
                    String gender = mcur.getString(1);
                    int age = mcur.getInt(2);
                   
                    try {
   // put your url here
                        URL url = new URL("http://www.exmple.com");
                        HttpURLConnection urlc = (HttpURLConnection)   url.openConnection();
                        urlc.setRequestProperty("Connection", "close");
                        urlc.setConnectTimeout(1000 * 30); // mTimeout is in seconds
                                urlc.connect();
                        if (urlc.getResponseCode() == 200) {
                           
                            Log.d("Response", "==200");
                            Toast.makeText(MainActivity.this, "Successfull", Toast.LENGTH_LONG).show();
                           
                            // Delete DataBase
                            mDB = dbHelper.getWritableDatabase();
                            mDB.execSQL("DROP TABLE "+DataBaseHelper.USER_TABLE);
                            dbHelper.onCreate(mDB);
                        }
                    }  catch (IOException e) {
                        Toast.makeText(MainActivity.this, "Faild", Toast.LENGTH_LONG).show();
                        Log.d("Response", "!=200");
                        e.printStackTrace();
                    } 
                   
                    Log.d("DATA", "Name : "+name+", Gender : "+gender+", Age : "+age);
                    mcur.moveToNext();
                    mDB.close();
                }
               
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
   
}

 // NewForm.java   // class

package com.example.userdetail;

import android.app.Activity;
import android.content.ContentValues;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class NewForm extends Activity{
   
    EditText name,age;
    Button savetoDb;
    RadioGroup radioSexGroup;
    RadioButton radioSexButton;
    DataBaseHelper dbHelper;
    SQLiteDatabase mDB;
    boolean isUpdate;
    String id,uName,uAge,uGen;
   
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.form);
       
        name = (EditText)findViewById(R.id.ename);
        age = (EditText)findViewById(R.id.eage);
        radioSexGroup = (RadioGroup)findViewById(R.id.radiogender);
        savetoDb = (Button)findViewById(R.id.savetoSqlite);
       
        isUpdate = getIntent().getExtras().getBoolean("update");
       
        if(isUpdate){
            id = getIntent().getExtras().getString("id");
            uName = getIntent().getExtras().getString("name");
            uAge = getIntent().getExtras().getString("age");
        //    uGen = getIntent().getExtras().getString("gender");
           
            name.setText(uName);
            age.setText(uAge);
        //    radioSexButton.setText(uGen);
        }
       
        savetoDb.setOnClickListener(new View.OnClickListener() {
           
            @Override
            public void onClick(View v) {
               
                dbHelper = new DataBaseHelper(NewForm.this);
                mDB = dbHelper.getWritableDatabase();
               
                int selectedId = radioSexGroup.getCheckedRadioButtonId();
                radioSexButton = (RadioButton)findViewById(selectedId);
               
                String uName = name.getText().toString();
                String uSex = radioSexButton.getText().toString();
                String uAge  = age.getText().toString();
                int intAge = Integer.parseInt(uAge);
               
                ContentValues cv = new ContentValues();
                cv.put(DataBaseHelper.NAME, uName);
                cv.put(DataBaseHelper.GENDER, uSex);
                cv.put(DataBaseHelper.AGE,intAge );
               
                if(isUpdate){
                    // update database with new data
                    mDB.update(DataBaseHelper.USER_TABLE, cv, DataBaseHelper.KEY_ID +"="+id, null);
                }else{
                    // insert new data into database 
                mDB.insert(DataBaseHelper.USER_TABLE, null, cv);
                }
               
                Toast.makeText(getApplicationContext(),"Name : "+uName+",Age : "+intAge+", Sex :" +radioSexButton.getText(), Toast.LENGTH_LONG).show();
                mDB.close();
                finish();
            }
        });
       
    }

}

// DataBaseHelper.java

package com.example.userdetail;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DataBaseHelper extends SQLiteOpenHelper{
   
    public static final int DB_VERSION = 1;
    public static final String DATABASE_NAME = "details.db";
    public static final String USER_TABLE = "user_detail";
    public static final String KEY_ID = "id";
    public static final String NAME = "name";
    public static final String GENDER = "gender";
    public static final String AGE = "age";
   

    public DataBaseHelper(Context ctx) {
        super(ctx, DATABASE_NAME, null, DB_VERSION);
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        String TABLE = "CREATE TABLE "+USER_TABLE+"("+KEY_ID+" INTEGER PRIMARY KEY, "+NAME+" TEXT,"
                       +GENDER+" INTEGER,"+AGE+" INTEGER"+")";
        db.execSQL(TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS "+USER_TABLE);
        onCreate(db);
    }
   

}

 // DataList.java  

package com.example.userdetail;

import java.util.ArrayList;

import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Color;
import android.os.Bundle;
import android.support.v4.widget.SimpleCursorAdapter;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Toast;

public class DataList extends Activity{
    ListView listv;
    DataBaseHelper dbHelper;
    SQLiteDatabase mDB;
    Cursor mCur;
    View v;
   
    private ArrayList<String> userId = new ArrayList<String>();
    private ArrayList<String> user_fName = new ArrayList<String>();
    private ArrayList<String> user_age = new ArrayList<String>();
    private ArrayList<String> user_gender = new ArrayList<String>();
   
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.displaylist);
        listv = (ListView)findViewById(R.id.list);
        v = (View)findViewById(R.id.view);
       
        v.setBackgroundColor(Color.BLUE);
   
        // edit datalist
        listv.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView <?>args0,View args1,int args2,long args3){
                Intent i = new Intent(getApplicationContext(),NewForm.class);
                i.putExtra("id", userId.get(args2));
                i.putExtra("name", user_fName.get(args2));
                i.putExtra("age", user_age.get(args2));
                i.putExtra("gender", user_gender.get(args2));
                i.putExtra("update", true);
                startActivity(i);
            }
        });
       
        dbHelper = new DataBaseHelper(DataList.this);
       
        displayData();
       
    }
   
@SuppressWarnings("static-access")
private void displayData() {
    dbHelper = new DataBaseHelper(DataList.this);
        mDB = dbHelper.getWritableDatabase();
        String query = "SELECT "+"* "+"FROM "+DataBaseHelper.USER_TABLE;
        mCur = mDB.rawQuery(query, null);
    //    mCur = mDB.rawQuery("SELECT * FROM "+dbHelper.USER_TABLE,null );
        userId.clear();
        user_fName.clear();
        user_age.clear();
        user_gender.clear();
        if(mCur.moveToFirst()){
            do{
                userId.add(mCur.getString(mCur.getColumnIndex(dbHelper.KEY_ID)));
                user_fName.add(mCur.getString(mCur.getColumnIndex(dbHelper.NAME)));
                user_age.add(mCur.getString(mCur.getColumnIndex(dbHelper.AGE)));
                user_gender.add(mCur.getString(mCur.getColumnIndex(dbHelper.GENDER)));
            }while(mCur.moveToNext());
        }
        DisplayAdapter disadpt = new DisplayAdapter(DataList.this,userId, user_fName, user_age,user_gender);
        listv.setAdapter(disadpt);
        mCur.close();
    }
   
@Override
protected void onResume() {
   
    super.onResume();
    displayData();
}

}

// DisplayAdapter

package com.example.userdetail;

import java.util.ArrayList;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class DisplayAdapter extends BaseAdapter{
   
    private Context ctx;
    private ArrayList<String>id;
    private ArrayList<String>name;
    private ArrayList<String>age;
    private ArrayList<String>gender;
   
    public DisplayAdapter(Context c,ArrayList<String>id,ArrayList<String>name,ArrayList<String>age,ArrayList<String>gen){
        this.ctx = c;
        this.id = id;
        this.name = name;
        this.age = age;
        this.gender = gen;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return id.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int pos, View child, ViewGroup parent) {
        Holder mHolder;
        LayoutInflater layoutinflater;
        if(child == null){
            layoutinflater = (LayoutInflater)ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            child = layoutinflater.inflate(R.layout.listcell, null);
            mHolder = new Holder();
            mHolder.txt_id = (TextView)child.findViewById(R.id.txt_id);
            mHolder.txt_name = (TextView)child.findViewById(R.id.txt_name);
            mHolder.txt_age = (TextView)child.findViewById(R.id.txt_age);
            mHolder.txt_gen = (TextView)child.findViewById(R.id.txt_gender);
            child.setTag(mHolder);
        }else{
            mHolder = (Holder)child.getTag();
        }
        mHolder.txt_id.setText(id.get(pos));
        mHolder.txt_name.setText(name.get(pos));
        mHolder.txt_age.setText(age.get(pos));
        mHolder.txt_gen.setText(gender.get(pos));
        return child;
    }
   
    public class Holder{
        TextView txt_id;
        TextView txt_name;
        TextView txt_age;
        TextView txt_gen;
    }

}

/Layout
// activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dip"
    android:gravity="center_vertical">

    <Button
        android:id="@+id/nform"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"      
        android:text="New Form" />
   
    <Button
        android:id="@+id/edit"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dip"     
        android:text="Edit" />
   
    <Button
        android:id="@+id/sendtoserver"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dip"     
        android:text="Send to Server" />
   
    <Button
        android:id="@+id/delete_db"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dip"     
        android:text="Delete DATA" />

</LinearLayout>

// form.xml

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
       
    <EditText
        android:id="@+id/ename"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="50dip"
        android:layout_marginLeft="20dip"
        android:layout_marginRight="20dip"
        android:layout_marginBottom="25dip"
        android:hint="Enter Name"
        android:inputType="text">
        <requestFocus/>
    </EditText>
   
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dip"
        android:layout_marginRight="20dip"
        android:layout_marginBottom="5dip"
        android:textSize="15dip"
        android:text="Gender:"/>
   
    <RadioGroup
        android:id="@+id/radiogender"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginRight="20dip"
        android:layout_marginLeft="20dip">
       
        <RadioButton
            android:id="@+id/male"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Male"
            android:checked="true"/>
       
        <RadioButton
            android:id="@+id/female"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="female"/>
       
    </RadioGroup>
   
    <EditText
        android:id="@+id/eage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:hint=" Age "
        android:inputType="number"
        android:layout_marginTop="20dip"
        android:layout_marginLeft="20dip"
        android:layout_marginRight="20dip">     
    </EditText>
   
    <Button android:id="@+id/savetoSqlite"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Save Data"
        android:layout_marginTop="20dip"
        android:layout_marginLeft="20dip"
        android:layout_marginRight="20dip"/>
       
       
   </LinearLayout>

// displaylist.xml

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
   
    <LinearLayout
   
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#F3CAE5"
    android:gravity="center_vertical"
    android:orientation="horizontal"
    android:padding="8dp" >
   
    <TextView
       
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="ID"
        android:textColor="#000" />

    <TextView
        android:text="Name"
        android:layout_width="55dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:textColor="#000" />

    <TextView
        android:text="Gender"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        android:textColor="#000" />

    <TextView
        android:text="Age"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        android:textColor="#000" />

</LinearLayout>

    <View android:id="@+id/view"
        android:layout_width="fill_parent"
        android:layout_height="2dip"  /> 

    <ListView
        android:id="@+id/list"
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:divider="#8DB3E1"
        android:dividerHeight="1dp">
    </ListView>
         
   
</LinearLayout>

//listcell.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#F3CAE5"
    android:gravity="center_vertical"
    android:orientation="horizontal"
    android:padding="8dp" >
   
   
    <TextView
        android:id="@+id/txt_id"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:textSize="17dp"
        android:textColor="#000" />

    <TextView
        android:id="@+id/txt_name"
        android:layout_width="55dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
         android:textSize="17dp"
        android:textColor="#000" />

    <TextView
        android:id="@+id/txt_gender"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="2"
         android:textSize="17dp"
        android:textColor="#000" />

    <TextView
        android:id="@+id/txt_age"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="2"
         android:textSize="17dp"
        android:textColor="#000" />

</LinearLayout>

// UserDetailManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.userdetail"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/userTheme" >
        <activity
            android:name="com.example.userdetail.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".NewForm"/>
        <activity
            android:name=".DataList"/>
    </application>

</manifest>

Building Web Apps in WebView

If you want to deliver a web application (or just a web page) as a part of a client application, you can do it using WebView. The WebView class is an extension of Android's View class that allows you to display web pages as a part of your activity layout.It does not include any features of a fully developed web browser, such as navigation controls or an address bar. All that WebView does, by default, is show a web page.

Create your layout: activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<WebView 
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/webView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />

within your Activity: MainActivity.java

import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends Activity {
    WebView webView;

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       
        webView = (WebView)findViewById(R.id.webView1);
        webView.getSettings().setJavaScriptEnabled(true);
// Handling page navigation
        webView.setWebViewClient(new WebViewClient());
        webView.loadUrl("http://ashfaquedl.blogspot.in/");
        webView.getSettings().setSupportZoom(true);
        webView.getSettings().setBuiltInZoomControls(true);
    }
//  Navigating web page history
    @Override
    public void onBackPressed() {
        if (webView.copyBackForwardList().getCurrentIndex() > 0) {
            webView.goBack();
        }
        else {
            // Your exit alert code, or alternatively line below to finish
            super.onBackPressed(); // finishes activity
        }
    }

}
 Note: And most important thing don't forget to add below uses-permission in AndroidMenifest.xml.
<uses-permission android:name="android.permission.INTERNET"/>
now your app is rocking.
 

How to clear cache in Android Manually & Programmatically

What the android os does is when you exit an application it actually stores the apps cache on either your phones internal storage or on the sdcard; so what this does, is that when you load the application next time, it immediately loads the stored cache back into your active cache for the purpose of speeding up loading time. So in theory, stored cache is actually a good thing.
However, this is not always the case.
Its only really a beneficial feature for certain applications, like Google maps, where loading all those images normally takes a long time (relatively speaking of course.. its still really fast). An even better example would be your launcher app; your always loading the exact same homescreens everytime. But for other apps it actually is a bad thing and bogs your system down. Why? Because your taking over the fastest available memory on your device with stored data that might not be essential/relevant for what your doing the next time you load the application. A good example would be your web browser. The last time you ran it you were checking the news or watching youtube videos... but now your just doing a google search; you certainly don't need to load the cache from your last session. Get it? 
Clear Cache manually 
< Applications --> Manage Applications --> "My App" --> Clear Cache>> 
Clear cache programmatically

import java.io.File;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;

public class HelloWorld extends Activity {

   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle *) {
      super.onCreate(*);
      setContentView(R.layout.main);
   }

   @Override
   protected void onStop(){
      super.onStop();
   }

   //Fires after the OnStop() state
   @Override
   protected void onDestroy() {
      super.onDestroy();
      try {
         trimCache(this);
      } catch (Exception e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
      }
   }

   public static void trimCache(Context context) {
      try {
         File dir = context.getCacheDir();
         if (dir != null && dir.isDirectory()) {
            deleteDir(dir);
         }
      } catch (Exception e) {
         // TODO: handle exception
      }
   }

   public static boolean deleteDir(File dir) {
      if (dir != null && dir.isDirectory()) {
         String[] children = dir.list();
         for (int i = 0; i < children.length; i++) {
            boolean success = deleteDir(new File(dir, children[i]));
            if (!success) {
               return false;
            }
         }
      }

      // The directory is now empty so delete it
      return dir.delete();
   }

}

  
 

How to save SMS to INBOX in Android Programmatically


There is below code

                ContentValues values = new ContentValues();
                values.put("address", "123456789");
                values.put("body", "foo bar");
                getContentResolver().insert(Uri.parse("content://sms/inbox"), values);

you can save SMS to Sent box also just require to few change.
Replace  ("content://sms/inbox") to ("content://sms/sent").



Below Android Permissions required

    <uses-permission android:name="android.permission.READ_SMS"/>
    <uses-permission android:name="android.permission.WRITE_SMS"/>

How to access Gmail Particular Label content programmatically


              javax.mail.Folder inbox = store.getFolder("SMS");
              inbox.open(Folder.READ_WRITE);
              Message messages[] = inbox.getMessages();
              int count =  messages.length;
              Log.d("SMS count ", ""+count);
              for (Message message : messages){
            // System.out.println(message);
              Log.d("inbox msssgggggg ", "Sub : "+message.getSubject()
                      +" Body :"+message.getContent().toString() +" From
                       :"+message.getFrom());
              }

          Where store is IMAPStore object

how to get / find your device IMEI number programmatically in andorid 

 

TelephonyManager telephonyManager = 

         (TelephonyManager) this.getSystemService(

         Context.TELEPHONY_SERVICE);
String IMEI_Number = telephonyManager.getDeviceId();
Log.d("your device IMEI number -->",IMEI_Number); 

Requires permission android.permission.READ_PHONE_STATE. 

Dial *#06# to know your IMEI Number or Remove 

your battery and look for IMEI,you will find it.

 

AsyncTask

AsyncTask enables proper and easy use of the UI thread. This class allows to perform background operations and publish results on the UI thread without having to manipulate threads and/or handlers.

AsyncTask is designed to be a helper class around Thread and Handler and does not constitute a generic threading framework. AsyncTasks should ideally be used for short operations (a few seconds at the most.) If you need to keep threads running for long periods of time, it is highly recommended you use the various APIs provided by the java.util.concurrent pacakge such as Executor, ThreadPoolExecutor and FutureTask.
An asynchronous task is defined by a computation that runs on a background thread and whose result is published on the UI thread. An asynchronous task is defined by 3 generic types, called Params, Progress and Result, and 4 steps, called onPreExecute, doInBackground, onProgressUpdate and onPostExecute.

Usage

---

AsyncTask must be subclassed to be used. The subclass will override at least one method (doInBackground(Params...)), and most often will override a second one (onPostExecute(Result).)

 private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> {
     protected Long doInBackground(URL... urls) {
         int count = urls.length;
         long totalSize = 0;
         for (int i = 0; i < count; i++) {
             totalSize += Downloader.downloadFile(urls[i]);
             publishProgress((int) ((i / (float) count) * 100));
             // Escape early if cancel() is called
             if (isCancelled()) break;
         }
         return totalSize;
     }

     protected void onProgressUpdate(Integer... progress) {
         setProgressPercent(progress[0]);
     }

     protected void onPostExecute(Long result) {
         showDialog("Downloaded " + result + " bytes");
     }
 }

Once created, a task is executed very simply:

 new DownloadFilesTask().execute(url1, url2, url3);
 

AsyncTask's generic types

---

The three types used by an asynchronous task are the following:

1. Params, the type of the parameters sent to the task upon execution.
2. Progress, the type of the progress units published during the background computation.
3. Result, the type of the result of the background computation.

Not all types are always used by an asynchronous task. To mark a type as unused, simply use the type Void:

 private class MyTask extends AsyncTask<Void, Void, Void> { ... }