Sample JSON file assets parse using GSON

Right now in my Android Development journey Google GSON becomes my favorite arsenal for
converting JSON to Java objects vice versa. 

Benefits using GSON:


1. Its very handy to use.
2. The number of codes will be lessen.
3. Once you converted Java objects to JSON you can now pass it thru intent bundle as a String.


Heres a step by step sample How GSON can help you to parse JSON objects To Java Pojo.

GSON PART:

1.) Create a directory under main folder name it “assets”
src > main > assets

2.) Create a File “androidwear.json”

src > main > assets > androidwear.json

	{
	"watches": [
	{
	"name" : "ZTE quartz",
	"price": "$130"
	},
	{
	"name" : "New Balance RunIQ",
	"price": "$190"
	},
	{
	"name" : "Casio PRO TREK Smart",
	"price": "$159"
	},
	{
	"name" : "LG Watch Style",
	"price": "$170"
	},
	{
	"name" : "LG Watch Sport",
	"price": "$220"
	},
	{
	"name" : "Michael Kors Smart Watch",
	"price": "$322"
	},
	{
	"name" : "Montblanc Summit",
	"price": "$200"
	},
	{
	"name" : "Huawei Watch 2",
	"price": "$199"
	},
	{
	"name" : "Polar M600",
	"price": "$212"
	}
	]
	}

view raw androidwear.json hosted with ❤ by GitHub

3.) Create class name “BaseWatch.java”
src > main > java > {package name} > BaseWatch.java
Basically this BaseWatch will serve as JSON parser that uses Google GSON library.

	package com.eugenealvizo.samplegson;
	import com.google.gson.annotations.Expose;
	import com.google.gson.annotations.SerializedName;
	import java.util.ArrayList;
	import java.util.List;
	/**
	* Created by eugene on 5/18/17.
	*/
	public class BaseWatch {
	@SerializedName("watches")
	@Expose
	private List<Watch> watches = new ArrayList<>();
	public List<Watch> getWatches() {
	return watches;
	}
	public void setWatches(List<Watch> watches) {
	this.watches = watches;
	}
	}

view raw BaseWatch.java hosted with ❤ by GitHub

4.) Create Class name “Watch.java”
src > main > java > {package name} > Watch.java
This class also serve as JSON parser it will get the inner data of androidwear.json

	package com.eugenealvizo.samplegson;
	import com.google.gson.annotations.Expose;
	import com.google.gson.annotations.SerializedName;
	/**
	* Created by eugene on 5/18/17.
	*/
	public class Watch {
	@SerializedName("name")
	@Expose
	private String name;
	@SerializedName("price")
	@Expose
	private String price;
	public String getName() {
	return name;
	}
	public void setName(String name) {
	this.name = name;
	}
	public String getPrice() {
	return price;
	}
	public void setPrice(String price) {
	this.price = price;
	}
	}

view raw Watch.java hosted with ❤ by GitHub

VIEW PART:


5.) After doing the 4 steps above we need to create two layouts for the Activity and Adapter;


5.1) Create a xml file “activity_main.xml”
res > layout > activity main.xml
this will serves as the main display container of the app.

	<?xml version="1.0" encoding="utf-8"?>
	<RelativeLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="match_parent"
	android:layout_height="match_parent">
	<ListView
	android:id="@+id/listView"
	android:layout_width="match_parent"
	android:layout_height="match_parent">
	</ListView>
	</RelativeLayout>

view raw activity_main.xml hosted with ❤ by GitHub





 5.2) Create a xml file “list_item_watch.xml”
res > layout > list_item_watch.xml
this will be the view for the list item.

	<?xml version="1.0" encoding="utf-8"?>
	<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="horizontal"
	android:layout_width="match_parent"
	android:layout_height="120dp">
	<TextView
	android:id="@+id/watchnameTxt"
	android:layout_width="0dp"
	android:layout_height="match_parent"
	android:layout_weight=".1"
	android:gravity="center"
	android:text="Watches Name"
	android:textSize="15dp"
	android:textStyle="bold"
	/>
	<TextView
	android:id="@+id/watchpriceTxt"
	android:layout_width="0dp"
	android:layout_height="match_parent"
	android:layout_weight=".1"
	android:gravity="center"
	android:text="$200"
	android:textSize="15dp"
	android:textColor="@color/colorAccent"/>
	</LinearLayout>

view raw listitem_watch.xml hosted with ❤ by GitHub

6.) Once you already finished creating the two layouts, the next step will be create the “MainActivity.java”.
src > main > java > {package name } > MainActivity.java

	package com.eugenealvizo.samplegson;
	import android.support.v7.app.AppCompatActivity;
	import android.os.Bundle;
	import android.util.Log;
	import android.widget.ListView;
	import java.io.IOException;
	import java.io.InputStream;
	import java.util.List;
	import com.google.gson.Gson;
	public class MainActivity extends AppCompatActivity {
	private final static String JSON_FILE_ANDROID_WEAR = "androidwear.json";
	private final static String TAG = "MainActivity";
	private WatchAdapter watchAdapter;
	private ListView listView;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	init();
	}
	public void init() {
	listView = (ListView) findViewById(R.id.listView);
	watchAdapter = new WatchAdapter(MainActivity.this, getWatchesData());
	listView.setAdapter(watchAdapter);
	}
	/* Convert JSON String to BaseWatch Model via GSON */
	public List<Watch> getWatchesData() {
	String jsonString = getAssetsJSON(JSON_FILE_ANDROID_WEAR);
	Log.d(TAG, "Json: " + jsonString);
	Gson gson = new Gson();
	BaseWatch baseWatch = gson.fromJson(jsonString, BaseWatch.class);
	return baseWatch.getWatches();
	}
	/* Get File in Assets Folder */
	public String getAssetsJSON(String fileName) {
	String json = null;
	try {
	InputStream inputStream = this.getAssets().open(fileName);
	int size = inputStream.available();
	byte[] buffer = new byte[size];
	inputStream.read(buffer);
	inputStream.close();
	json = new String(buffer, "UTF-8");
	} catch (IOException e) {
	e.printStackTrace();
	}
	return json;
	}
	}

view raw MainActivity.java hosted with ❤ by GitHub

7.) After that, Create a class “WatchAdapter.java” this class will be the incharge of inflating the data to ListItem.

src > main > java > {package name } > WatchAdapter.java

	package com.eugenealvizo.samplegson;
	import android.content.Context;
	import android.view.LayoutInflater;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.BaseAdapter;
	import android.widget.TextView;
	import java.util.List;
	/**
	* Created by eugene on 5/18/17.
	*/
	public class WatchAdapter extends BaseAdapter {
	Context context;
	List<Watch> dataList;
	private View vi;
	private ViewHolder viewHolder;
	private static LayoutInflater inflater = null;
	public WatchAdapter(Context context, List<Watch> dataList){
	this.context = context;
	this.dataList = dataList;
	inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
	}
	@Override
	public int getCount() {
	return dataList.size();
	}
	@Override
	public Object getItem(int i) {
	return i;
	}
	@Override
	public long getItemId(int i) {
	return i;
	}
	@Override
	public View getView(int position, View view, ViewGroup viewGroup) {
	vi = view;
	//Populate the Listview
	final int pos = position;
	Watch watch = dataList.get(pos);
	if(vi == null) {
	vi = inflater.inflate(R.layout.listitem_watch, viewGroup, false);
	viewHolder = new ViewHolder();
	viewHolder.name = (TextView) vi.findViewById(R.id.watchnameTxt);
	viewHolder.price = (TextView) vi.findViewById(R.id.watchpriceTxt);
	vi.setTag(viewHolder);
	}else
	viewHolder = (ViewHolder) view.getTag();
	viewHolder.name.setText(watch.getName());
	viewHolder.price.setText(watch.getPrice());
	return vi;
	}
	public class ViewHolder{
	TextView name;
	TextView price;
	}
	}

view raw WatchAdapter.java hosted with ❤ by GitHub


 Note: If you are still not knowledgable with BaseAdapter you can visit this first readme



 8.) Heres my default Build Gradle Dependencies together with Google GSON




	dependencies {
	compile fileTree(dir: 'libs', include: ['*.jar'])
	androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
	exclude group: 'com.android.support', module: 'support-annotations'
	})
	compile 'com.android.support:appcompat-v7:25.2.0'
	compile 'com.android.support.constraint:constraint-layout:1.0.2'
	testCompile 'junit:junit:4.12'
	compile 'com.google.code.gson:gson:2.8.0'
	}

view raw build.gradle hosted with ❤ by GitHub

SCREENSHOT



Download Source Code via Github

SQlite Manager for browsing data in Android

Hello Guys!

Common questions of new Android Developers today is how they can view the data that are stored in their Android App, So I decided to share two tools that I'm using to browse Sqlite data in my Android App.

1. ADM - Android Device Monitor.
- ADM is a part/feature of Android Studio that can monitor your Device that is currently connected in your machine.
2. Mozilla Firefox with SQLite Manager extension.

- It acts like File Manager of SQlite files.

features:
a. You can execute Query.
b. You can alter Database.
c. Show all stored data.
d. and many more! :)


Here's the steps to extract SQLite: *Note I used Genymotion Emulator as my Device

1. Open your Project in Android Studio, As for me I opened my com.hnh.tourme project

2. Click tools in the upper menu of Android Studio, and then click Android Device Monitor (ADM)

3. Then ADM window will appear. Your current tab must be in the File Explorer, And the go to /data/data/[packagename]/databases/[dbName] after that click the Sqlite File and click pull file from device Icon.

(As for me my database name is clean_home so my Directory will be /data/data/com.hnh.tourme/databases/clean_home)

4. Open your Mozilla Firefox and Install Sqlite Manager as an extension, after installing open new window for Sqlite Manager and then import the Sqlite file which is clean_home.sqlite. DONE! :)

[ButterKnife] Sum and Diff Simple Android App

Hello Guys!

 In Android development, One of the famous open source library  is Butterknife. What is ButterKnife? A Library that binds your Android views which uses annotation process. built by Jake Wharton.
- Very light weight.
- Eliminates long codes in finding your Android views.
- It uses annotation such as @Bind, @OnClick and more.
- Clean code and organize.
- Binds String resources.

Personally I always includes this library in most of my projects , I highly recommend you guys to use this, it will improve your speed in production.

 you can add this library using Gradle system of Android studio

dependencies {
   compile 'com.jakewharton:butterknife:7.0.1'
}

After syncing your Gradle, you can now use Butterknife in your project.

Here's My Example Android App that can get the Sum or Diff of two numbers.

1.MainActivity.java

package com.example.uge.butterknifesample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import butterknife.Bind;
import butterknife.ButterKnife;
import butterknife.OnClick;

public class MainActivity extends AppCompatActivity {

    @Bind(R.id.firstNum)
    EditText firstNum;

    @Bind(R.id.secondNum)
    EditText secondNum;


    @Bind(R.id.answerText)
    TextView answerTxt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);

    }

    @OnClick(R.id.sumBtn)
    void getTheSumOfTwoNumbers(){
        if(validateEditText()){
            int fValue = Integer.parseInt(firstNum.getText().toString());
            int sValue = Integer.parseInt(secondNum.getText().toString());
            int sumValue = fValue + sValue;
            answerTxt.setText("Sum: " + sumValue);
        }else{
            Toast.makeText(this, "Please Input the Values in the EditText(s)", Toast.LENGTH_SHORT).show();
        }
        hideKeyboard();
    }

    @OnClick(R.id.diffBtn)
    void getTheDiffOfTwoNumbers(){
        if(validateEditText()){
            int fValue = Integer.parseInt(firstNum.getText().toString());
            int sValue = Integer.parseInt(secondNum.getText().toString());
            int diffValue = fValue - sValue;
            answerTxt.setText("Diff: " + diffValue);
        }else{
            Toast.makeText(this, "Please Input the Values in the EditText(s)", Toast.LENGTH_SHORT).show();
        }
        hideKeyboard();
    }

    public Boolean validateEditText(){
        //The Two EditText must have a value
        if(firstNum.getText().toString().length() > 0 && secondNum.getText().toString().length() > 0){
            return true;
        }else{
            return false;
        }
    }

    public void hideKeyboard(){
        InputMethodManager imm = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
        if(imm.isAcceptingText()) { // verify if the soft keyboard is open
            imm.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
        }
    }

}

2. Layout (activity_main.xml)

<?xml version="1.0" encoding="utf-8"?>
<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:layout_margin="15dp"
    tools:context="com.example.uge.butterknifesample.MainActivity">

    <EditText
        android:id="@+id/firstNum"
        android:layout_width="match_parent"
        android:layout_height="45dp"
        android:inputType="number"
        android:hint="First Number" />

    <EditText
        android:id="@+id/secondNum"
        android:layout_width="match_parent"
        android:layout_height="45dp"
        android:hint="Second Number"
        android:inputType="number"
        android:layout_below="@+id/firstNum" />

    <Button
        android:id="@+id/sumBtn"
        android:layout_width="match_parent"
        android:layout_height="45dp"
        android:text="Sum"
        android:layout_below="@+id/secondNum"
        android:layout_margin="5dp"/>
    <TextView
        android:id="@+id/orText"
        android:layout_below="@+id/sumBtn"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="OR"
        android:layout_margin="5dp"/>
    <Button
        android:id="@+id/diffBtn"
        android:layout_width="match_parent"
        android:layout_height="45dp"
        android:text="Difference"
        android:layout_below="@+id/orText"
        android:layout_margin="5dp"/>


    <TextView
        android:id="@+id/answerText"
        android:textSize="20sp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"/>

</RelativeLayout>

Here's the OUTPUT:

 


You can download the sources code here: ButterknifeSample


for automation of binding views in Butterknife you can use Butterknife zelezny

Downloading Bulk Images in Android

Hello Android Geeks,

Recently, I got an Android app project in my current work, Wherein the App needs to download bulk images via Webservices/API,
and the requirement of the process of downloading the assets is must be synchronous.

Here's is the sample code that I made to showcase the Android Library of NOSTRA13
entitle "Android-Universal-Image-Loader". for more info about this visit his GITHUB REPO

1.Download and compile the UIL in the Gradle's dependency

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.2.0'
}

2.Setup your Android Manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.sample.xeugene.imagedownload" >

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

    <application
        android:name=".App"
        android:allowBackup="true"
        android:icon="@mipmap/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>
    </application>

</manifest>

3. MainActivity

package com.sample.xeugene.imagedownload;

import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import com.nostra13.universalimageloader.core.ImageLoader;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    final static String TAG = "MAIN_ACTIVITY";
    ImageLoader imageLoader;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageLoader = ImageLoader.getInstance();

        new DownloadThisImageFromUrl().execute();

    }
    //Running the method imageloader.loadImagesync() must be
    // run in the background thread of the App.
    public class DownloadThisImageFromUrl extends AsyncTask<String, String ,String> {
        @Override
        protected String doInBackground(String... strings) {
            for(String urls : listOfUrls()) {
                Bitmap image = imageLoader.loadImageSync(urls);
                Log.d(TAG, "Download Success: " + image);
                //You can use this var image to save in your SQLite DB :)
            }
            return null;
        }
        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            Log.d(TAG, "DOWNLOAD COMPLETE!");
        }
    }

    //Static list url of the Images
    //You can add your desired Images here :)
    public List<String> listOfUrls(){
        List<String> listUrl = new ArrayList<>();
        listUrl.add("http://dogzone.tcwebsites.netdna-cdn.com/wp-content/uploads/2015/01/Funny-dog-names.jpg");
        listUrl.add("http://dreamatico.com/data_images/dog/dog-5.jpg");
        listUrl.add("http://static.communitytable.parade.com/wp-content/uploads/2014/02/labrador-america-top-dog-breed-ftr.jpg");
        return  listUrl;
    }
}

4. Instantiate the Universal Image Loader library in the Application (Singleton)

package com.sample.xeugene.imagedownload;

import android.app.Application;
import android.content.Context;

import com.nostra13.universalimageloader.cache.memory.impl.WeakMemoryCache;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.ImageScaleType;
import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer;

/**
 * Created by EugeneAllen on 9/22/2015.
 */
public class App extends Application {


    @Override
    public void onCreate() {
        super.onCreate();

        initImageLoader(getApplicationContext());
    }

    public static void initImageLoader(Context context) {
        DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
                .cacheOnDisc(true).cacheInMemory(true)
                .imageScaleType(ImageScaleType.EXACTLY)
                .displayer(new FadeInBitmapDisplayer(300)).build();

        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(
                context)
                .defaultDisplayImageOptions(defaultOptions)
                .memoryCache(new WeakMemoryCache())
                .discCacheSize(100 * 1024 * 1024).build();

        ImageLoader.getInstance().init(config);
    }
}

Using Shared Preferences in Setting Screen

Hi Guys I'm back! Today, My topic is all about Shared Preferences of Android. What is Shared Preference? a class that allows you to save and retrieve persistent key-value pairs of primitive data types(booleans, floats, ints, longs, and strings). This sample code may give you idea how to use Shared Preference in your Android App Projects. I used Shared Preference in saving my Settings, The scenario is if the user wants to save his/her setting in the app for example, turning on/ turning off the Music, Sounds and Updates. Note: This data will persist across user sessions (even if your application is killed).

import android.app.Activity;
import android.content.SharedPreferences;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Switch;
import android.widget.Toast;


public class MainActivity extends ActionBarActivity {

    Switch musicSwitch;
    Switch soundsSwitch;
    Switch updatesSwitch;

    Button saveBtn;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        musicSwitch = (Switch) findViewById (R.id.switch1);
        soundsSwitch = (Switch) findViewById (R.id.switch2);
        updatesSwitch = (Switch) findViewById (R.id.switch3);
        saveBtn = (Button) findViewById (R.id.buttonSave);

        setWidget();
        saveBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                savePreferences();
            }
        });

    }

    private void setWidget(){
        //Get the value of SharedPref if null return false 
        SharedPreferences customSharedPreference = getSharedPreferences("mySettings", Activity.MODE_PRIVATE);
        updatesSwitch.setChecked(customSharedPreference.getBoolean("updates",false));
        musicSwitch.setChecked(customSharedPreference.getBoolean("music",false));
        soundsSwitch.setChecked(customSharedPreference.getBoolean("sounds",false));


    }
    private void savePreferences(){

        SharedPreferences myPref = getSharedPreferences("mySettings", Activity.MODE_PRIVATE);
        SharedPreferences.Editor editor = myPref.edit();
        //Setting the value of SharedPref
        editor.putBoolean("music", musicSwitch.isChecked());
        editor.putBoolean("sounds", soundsSwitch.isChecked());
        editor.putBoolean("updates", updatesSwitch.isChecked());
        editor.commit();

        Toast.makeText(this, "Setting Saved", Toast.LENGTH_SHORT).show();
    }

}

Layouts:

<RelativeLayout
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <Switch android:id="@+id/switch1"
        android:layout_centerInParent="true"
        android:layout_height="20dp"
        android:layout_width="wrap_content"
        android:text="Music"/>

    <Switch android:id="@+id/switch2"
        android:layout_height="20dp"
        android:layout_width="wrap_content"
        android:text="Sounds"
        android:layout_above="@+id/switch3"
        android:layout_alignLeft="@+id/switch3"
        android:layout_alignStart="@+id/switch3"
        android:layout_marginBottom="56dp" />


    <Switch android:id="@+id/switch3"
        android:layout_height="20dp"
        android:layout_width="wrap_content"
        android:text="Updates"
        android:layout_above="@+id/switch1"
        android:layout_alignLeft="@+id/switch1"
        android:layout_alignStart="@+id/switch1"
        android:layout_marginBottom="49dp" />

    <Button android:id="@+id/buttonSave"
        android:layout_height="45dp"
        android:layout_width="80dp"
        android:text="SAVE"
        android:layout_below="@+id/switch1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="58dp" />

</RelativeLayout>

Output:

Sample Ormlite for Android Database

Hi Guys, This post is all about Ormlite, so What is Ormlite?
Ormlite is an open source software framework that provides lightweight object relational mapping (ORM) between Java classes and SQL databases. It supports JDBC databases as well as Android mobile platform according. To see more documentations about Ormlite visit this (http://ormlite.com/)

Okay lets Start the Project!! :D

1st add this to your dependencies

Download Jar here

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:21.0.3'
    compile files('libs/ormlite-android-4.48.jar')
    compile files('libs/ormlite-core-4.48.jar')
}

1.MainActivity.java

package com.example.user.ormlite;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.j256.ormlite.android.apptools.OpenHelperManager;
import com.j256.ormlite.dao.RuntimeExceptionDao;
import java.util.List;

public class MainActivity extends ActionBarActivity {

    DataHelper dbHelper;
    Button save;
    Button viewAll;
    Button delete;
    EditText student_name;
    EditText student_lastname;
    EditText student_age;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //Get All Widget
        save = (Button) findViewById(R.id.btn_save);
        viewAll = (Button) findViewById(R.id.btn_view);
        delete = (Button) findViewById(R.id.btn_delete);
        student_name = (EditText) findViewById(R.id.name);
        student_lastname = (EditText) findViewById(R.id.surname);
        student_age = (EditText) findViewById(R.id.age);
        innit();
    }

    public void innit(){

        //OpenHelper of DatabaseHelper
        dbHelper = (DataHelper) OpenHelperManager.getHelper(this,DataHelper.class);
        final RuntimeExceptionDao<student integer=""> studDao = dbHelper.getStudRuntimeExceptionDao();
        save.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(student_name.getText().toString().length() &gt; 0 &amp;&amp; student_lastname.getText().toString().length() &gt; 0 &amp;&amp; student_age.getText().toString().length() &gt; 0) {
                    studDao.create(new Student(student_name.getText().toString(), student_lastname.getText().toString(), Integer.parseInt(student_age.getText().toString())));
                    student_name.setText("");
                    student_lastname.setText("");
                    student_age.setText("");
                    Toast.makeText(MainActivity.this, "Student Saved", Toast.LENGTH_SHORT).show();
                }
                else
                    Toast.makeText(MainActivity.this, "Please Complete all Inputs", Toast.LENGTH_SHORT).show();
            }
        });
        viewAll.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String display = "";
                List<student> students = studDao.queryForAll();
                for(Student holder : students){
                    display += holder.getFname() + " " +  holder.getLname() + " " +holder.getAge() + "\n";
                }
                Toast.makeText(MainActivity.this,"Students:" +  display, Toast.LENGTH_SHORT).show();
            }
        });
        delete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                List<student> students = studDao.queryForAll();
                studDao.delete(students);
                Toast.makeText(MainActivity.this,"Deleted", Toast.LENGTH_SHORT).show();
            }
        });

    }
    public void onDestroy(){
        super.onDestroy();
        OpenHelperManager.releaseHelper();
    }

}

2.Student.java Declaring your Database Table

import com.j256.ormlite.field.DatabaseField;
import com.j256.ormlite.table.DatabaseTable;

/**
 * Created by Eugene Alvizo on 1/4/2015.
 */

public class Student {

    //Database Field for Table Student
    @DatabaseField (generatedId = true)
    private int id;
    @DatabaseField
    private String fname;
    @DatabaseField
    private String lname;
    @DatabaseField
    private int age;

    //Constructors

    public Student() {
      //Adding a No-Argument-Constructor
    }

    public Student(String fname, String lname, int age) {
        this.fname = fname;
        this.lname = lname;
        this.age = age;
    }

    public Student(int id, String fname, String lname, int age) {
        this.id = id;
        this.fname = fname;
        this.lname = lname;
        this.age = age;
    }

    //Getters and Setters
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }


    public String getFname() {
        return fname;
    }

    public void setFname(String fname) {
        this.fname = fname;
    }

    public String getLname() {
        return lname;
    }

    public void setLname(String lname) {
        this.lname = lname;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

}

3.DataHelper.java Creating your Database

package com.example.user.ormlite;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper;
import com.j256.ormlite.dao.Dao;
import com.j256.ormlite.dao.RuntimeExceptionDao;
import com.j256.ormlite.support.ConnectionSource;
import com.j256.ormlite.table.TableUtils;

import java.sql.SQLException;

/**
 * Created by Eugene Alvizo on 1/4/2015.
 */
public class DataHelper extends OrmLiteSqliteOpenHelper {

    private Context context;
    private static final String DATABASE_NAME = "Student";
    private static final int DATABASE_VERSION = 1;

   
    private RuntimeExceptionDao<student integer=""> studRuntimeDAO = null;
    public DataHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
        this.context = context;
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase, ConnectionSource connectionSource) {
        try {
            TableUtils.createTable(connectionSource, Student.class);
        } catch (SQLException e){
            e.printStackTrace();
        }

    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, ConnectionSource connectionSource, int i, int i2) {
        try {
            TableUtils.dropTable(connectionSource, Student.class, true);
            onCreate(sqLiteDatabase,connectionSource);
        } catch (SQLException e) {
            e.printStackTrace();
        }

    }

    public RuntimeExceptionDao<student integer=""> getStudRuntimeExceptionDao(){
        if(studRuntimeDAO == null){
            studRuntimeDAO = getRuntimeExceptionDao(Student.class);
        }
        return studRuntimeDAO;

    }

}

4.activity_main.xml Layout for the App

<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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:gravity="center">
    <EditText
        android:layout_width="180dp"
        android:layout_height="45dp"
        android:hint="Name"
        android:id="@+id/name"/>
    <EditText
        android:layout_width="180dp"
        android:layout_height="45dp"
        android:hint="Lastname"
        android:id="@+id/surname"/>
    <EditText
        android:layout_width="180dp"
        android:layout_height="45dp"
        android:hint="Age"
        android:inputType="number"
        android:id="@+id/age"/>
    <Button
        android:layout_width="180dp"
        android:layout_height="45dp"
        android:text="Save"
        android:id="@+id/btn_save"/>
    <Button
        android:layout_width="180dp"
        android:layout_height="45dp"
        android:text="View All"
        android:id="@+id/btn_view"/>
        <Button
            android:layout_width="180dp"
            android:layout_height="45dp"
            android:text="Delete All"
            android:id="@+id/btn_delete"/>
    </LinearLayout>

</LinearLayout>

           
Download Source code (Android Studio Project) reference