Android Background Service

Hey, in this tutorial I will demonstrate how to enable your application to continue working in the background without requiring any user interaction.

To start with, first of all create 2 buttons to start and stop the background service.

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context="com.codingreedefined.backgroundservice.MainActivity" >

    <Button

        android:id="@+id/btnStartService"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="Start Service"

        android:onClick="startService"

    />

    

    <Button

        android:id="@+id/btnStopService"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_below="@+id/btnStartService"

        android:text="Stop Service"

        android:onClick="stopService"

    />

</RelativeLayout>

After creating the buttons write functions to start and stop the background service in MainActivity file.

package com.codingreedefined.backgroundservice;

import android.support.v7.app.ActionBarActivity;

import android.content.Intent;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

public class MainActivity extends ActionBarActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    @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;

    }

    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar item clicks here. The action bar will

        // automatically handle clicks on the Home/Up button, so long

        // as you specify a parent activity in AndroidManifest.xml.

        int id = item.getItemId();

        if (id == R.id.action_settings) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

    

    //Method to start the service

    public void startService(View view)

    {

    startService(new Intent(getBaseContext(), MyService.class));

    }

    

    //Method to start the service

    public void stopService(View view)

    {

    stopService(new Intent(getBaseContext(), MyService.class));

    }

    

}

Now create a new Java class named MyService and extend Service. Finally write the following code.

package com.codingreedefined.backgroundservice;

import android.app.Service;

import android.content.Intent;

import android.os.IBinder;

import android.widget.Toast;

public class MyService extends Service 

{

@Override

public IBinder onBind(Intent intent) {

// TODO Auto-generated method stub

return null;

}

@Override

public int onStartCommand(Intent intent, int flags, int startId)

{

//let it continue running until it is stopped

Toast.makeText(this, "Service Started!!!", Toast.LENGTH_SHORT).show();

return START_STICKY;

}

@Override

public void onDestroy()

{

super.onDestroy();

Toast.makeText(this, "Service Stopped!!!", Toast.LENGTH_SHORT).show();

}

}

Finally add <service /> tag in the manifest file and run the application.

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.codingreedefined.backgroundservice"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="21" />

    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name=".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>

        <service android:name=".MyService" />

    </application>

</manifest>

The following output shall be obtained.

Hide Source Code of Web Pages

<!DOCTYPE html>
<html>
<head>
<!-- Code to prevent use of Ctrl+U -->
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script>
$(document).on('keydown',function(e)
{
    var key = e.charCode || e.keyCode;
    if(key == 17 || key == 85)
        {
e.preventDefault();
}
});
</script>
</head>
<!-- Use oncontextmenu="return false" to disable right-click -->
<body oncontextmenu="return false">
<h2>Coding Redefined</h2>
</body>
</html>

Android SQL Lite

Learn to use pre-installed SQL Lite in your Android phone.

Create the following layout to proceed with the example.

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

    <TextView

        android:id="@+id/tv1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="Enter Text" />

    <EditText 

        android:id="@+id/et"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"        

        android:layout_below="@+id/tv1"

        android:hint="Enter Here"

        />

    

    <Button 

        android:id="@+id/delete"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_below="@+id/select"

        android:text="DELETE"

        />

    <Button

        android:id="@+id/update"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignBaseline="@+id/delete"

        android:layout_alignBottom="@+id/delete"

        android:layout_alignLeft="@+id/insert"

        android:text="UPDATE" />

    <Button

        android:id="@+id/select"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_centerVertical="true"

        android:text="SELECT" />

    <Button

        android:id="@+id/insert"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignBottom="@+id/select"

        android:layout_toRightOf="@+id/select"

        android:text="INSERT" />

    <TextView

        android:id="@+id/tv2"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignParentLeft="true"

        android:layout_below="@+id/et" />

    

</RelativeLayout>

Now make changes in the activity file.

package com.codingredefined.androidsqlite;

import java.util.Locale;

import android.os.Bundle;
import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity
{
EditText et;
TextView tv1,tv2;
Button select,insert,update,delete;
SQLiteDatabase db;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et=(EditText)findViewById(R.id.et);
tv1=(TextView)findViewById(R.id.tv1);
tv2=(TextView)findViewById(R.id.tv2);
select=(Button)findViewById(R.id.select);
insert=(Button)findViewById(R.id.insert);
update=(Button)findViewById(R.id.update);
delete=(Button)findViewById(R.id.delete);
//Create DB
db=openOrCreateDatabase("test.db",SQLiteDatabase.CREATE_IF_NECESSARY,null);
db.setVersion(1);
db.setLocale(Locale.getDefault());
db.setLockingEnabled(true);
//Create Table(s)
final String create="CREATE TABLE TEST(daat TEXT);";
db.execSQL(create);
Toast.makeText(this,"Table Created Successfully",Toast.LENGTH_SHORT).show();
select.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
select(v);
}
});
insert.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
insert(v);
}
});
delete.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
delete(v);
}
});
update.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
update(v);
}
});
}

//function to display data
public void up()
{
db=openOrCreateDatabase("test.db",SQLiteDatabase.CREATE_IF_NECESSARY,null);
tv2.setText("");
Cursor cr=db.query("TEST",null,null,null,null,null,null,null);
cr.moveToFirst();
while(cr.isAfterLast()==false)
{
tv2.append("\n"+cr.getString(0));
cr.moveToNext();
}
cr.close();
db.close();
}

public void select(View v)
{
up();
}

//function to insert
public void insert(View v)
{
db=openOrCreateDatabase("test.db",SQLiteDatabase.CREATE_IF_NECESSARY,null);
ContentValues cv=new ContentValues();
cv.put("daat",et.getText().toString());
long a=db.insert("TEST",null,cv);
db.close();
if(a!=0)
{
Toast.makeText(this,"Insert",Toast.LENGTH_SHORT).show();
up();
}
else
{
Toast.makeText(this,"ERROR",Toast.LENGTH_SHORT).show();
}
}

//function to delete
public void delete(View v)
{
db=openOrCreateDatabase("test.db",SQLiteDatabase.CREATE_IF_NECESSARY,null);
db.delete("TEST","daat=?",new String[]{et.getText().toString()});
db.close();
up();
}

//function to update
public void update(View v)
{
db=openOrCreateDatabase("test.db",SQLiteDatabase.CREATE_IF_NECESSARY,null);
ContentValues cv=new ContentValues();
cv.put("daat",et.getText().toString());
db.update("TEST",cv,"daat=?",new String[]{et.getText().toString()});
db.close();
up();
}

@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;
}

}

The output will be

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