Database Demo

Here I am sharing code for using Database (SQLite) in android and I hope this post will be useful for newbees to learn android widgets.


Here I am going to use Expandable List view to populate Table Values to Activity.

This Sample is Developed in Android 2.3.3 SDK.


main.xml


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

<TextView android:layout_height="wrap_content"
android:id="@+id/Name"
android:layout_width="fill_parent"
android:text="Name">
</TextView>

<EditText android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:id="@+id/EmpName"
android:inputType="text|textCapCharacters|textCapWords|textCapSentences|textAutoCorrect|textAutoComplete">
</EditText>

<TextView android:layout_height="wrap_content"
android:layout_width="fill_parent"
android:id="@+id/Age"
android:text="Age">
</TextView>

<EditText android:layout_height="wrap_content"
android:id="@+id/EmpAge"
android:inputType="number|numberSigned|numberDecimal"
android:layout_width="fill_parent">
</EditText>

<RelativeLayout android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/RelativeLayout">

<Button android:text="InsertValues"
android:id="@+id/AddDet"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10px">
</Button>

<Button android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:layout_toRightOf="@+id/AddDet"
android:text="ViewDetails"
android:id="@+id/ViewDet">
</Button>

</RelativeLayout>


</LinearLayout>



Main Activity (SQLiteTest.java)

This activity gets details from user and popups an alert dialog for successfull/failure in DB insertion and toast for the value inserted in DB. When user taps view details button displays Expandable list view activity.


import android.app.Activity;
import android.app.AlertDialog;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class SQLiteTest extends Activity {
    /** Called when the activity is first created. */

    protected Button insertButton, viewButton;
    protected EditText nameText, ageText;
    DBHelper helper;
    Context mContext = this;
    String dispData;

   
    protected OnClickListener onClickListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if (v.getId() == R.id.AddDet) {
                Toast.makeText(
                        getApplicationContext(),
                        "Name  " + nameText.getText().toString() + "Age "
                                + ageText.getText().toString(),
                        Toast.LENGTH_LONG).show();
                Employee emp=new Employee(nameText.getText().toString(), Integer.parseInt(ageText.getText().toString()));
                int status =helper.insertTable(emp);
                if (status != -1) {
                    AlertDialog.Builder alert = new AlertDialog.Builder(
                            mContext);
                    alert.setMessage("Table Values Inserted");
                    alert.setNeutralButton("OK",
                            new DialogInterface.OnClickListener() {

                       
                       
                                @Override
                                public void onClick(DialogInterface dialog,
                                        int which) {
                                    // TODO Auto-generated method stub
                                    dialog.cancel();
                                }
                            });
                    AlertDialog al = alert.create();
                    al.show();
                } else {
                    AlertDialog.Builder alert = new AlertDialog.Builder(
                            mContext);
                    alert.setMessage("Table Values not Inserted");
                    alert.setNeutralButton("OK",
                            new DialogInterface.OnClickListener() {

                                @Override
                                public void onClick(DialogInterface dialog,
                                        int which) {
                                    // TODO Auto-generated method stub
                                    dialog.cancel();
                                }
                            });
                    AlertDialog ad = alert.create();
                    ad.show();
                }   
            } else if (v.getId() == R.id.ViewDet) {
                Intent intent=new Intent(SQLiteTest.this,sample.class);
                startActivity(intent);
            }

        }
    };

    protected void notifyTrigger(CharSequence Title, CharSequence msg) {
        CharSequence sequence = Title;
        CharSequence message = msg;
        NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        Notification notification = new Notification(R.drawable.icon,
                "This is to Notify You", System.currentTimeMillis()) {
        };
        Intent notificationIntent = new Intent(this, SQLiteTest.class);
        PendingIntent pIntent = PendingIntent.getActivity(this, 0,
                notificationIntent, 0);
        notification.setLatestEventInfo(getApplicationContext(), sequence,
                message, pIntent);
        nm.notify(1, notification);
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        helper = new DBHelper(getApplicationContext());
        // helper.createTable();
        insertButton = (Button) findViewById(R.id.AddDet);
        viewButton = (Button) findViewById(R.id.ViewDet);
        nameText = (EditText) findViewById(R.id.EmpName);
        ageText = (EditText) findViewById(R.id.EmpAge);
        insertButton.setOnClickListener(onClickListener);
        viewButton.setOnClickListener(onClickListener);

              
    }
}

DBConnection Class (DBHelper.java)

This class creates Database and tables and inserts the value from the user input taken from POJO


import java.util.ArrayList;
import java.util.List;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteFullException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DBHelper extends SQLiteOpenHelper {

    private static final String dbName = "SampleDB";
    public final String tableName="TestTable";
    public final String attribValue1="Name";
    public final String attribValue2="age";
    SQLiteTest sqltest;
    String[] nameVal;
    int[] ageVal;
    int size;
    int i=0;
   
    public DBHelper(Context context) {
        super(context, dbName, null, 33);
        sqltest = new SQLiteTest();
        // TODO Auto-generated constructor stub
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        String sql="";
        try {
            //sql ="create table if not exists " + tableName + "(" +attribValue1 + "varchar" + attribValue2+ "int(3))";
            sql="CREATE TABLE "+tableName+"(Name TEXT,age INTEGER)";
            db.execSQL(sql);
        } catch(SQLiteFullException e) {
            e.getMessage();
            Log.d("Test", sql);   
        }
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub

    }
   
    public void createTable() {
        SQLiteDatabase db=this.getWritableDatabase();
        String query = "create table if not exists " + tableName + "("+ attribValue1 + "varchar(20)" + attribValue2    + "int(3))";
        db.execSQL(query);
        db.close();
    }
   
    public int insertTable(Employee emp){
        SQLiteDatabase db=this.getWritableDatabase();
        ContentValues cv=new ContentValues();
        cv.put("Name",emp.getName());
        cv.put("age", emp.getAge());
        int status=(int) db.insert(tableName, null, cv);
        db.close();
        return status;   
    }
   
    public List viewTable() {
        //String result="";
        List arrList=new ArrayList ();
        try {
            SQLiteDatabase db=this.getWritableDatabase();
            String query="select * from " + tableName;
            Log.d("query message  ", query);
            Cursor c = db.rawQuery(query, null);
             size=c.getCount();
            nameVal=new String[size];
            ageVal=new int[size];
           
            int col1 = c.getColumnIndex("Name");
            int col2 = c.getColumnIndex("age");
           
            c.moveToFirst();
            if (c != null) {
                do {
                    nameVal[i]=c.getString(col1);
                    ageVal[i]=c.getInt(col2);
                   
                   
                    //arrList.add(ageVal[i]+"");
                    //result=result+nameVal+" "+ageVal+" ";
                    System.out.println("Name     :"+nameVal[i]);
                    System.out.println("Age      :"+ageVal[i]);
                    i++;
                } while (c.moveToNext());
                arrList.add(nameVal);
                arrList.add(ageVal);
            }
           
            db.close();
        }catch(SQLiteFullException exp) {
             exp.getMessage();
             Log.d("Exception Cause", exp.getMessage());
         }
       
        return arrList;
       
    }

}


POJO for DB(Employee.java)

A POJO is simply a Java object that does not implement any special interfaces which is used to design simple Business Domains.

public class Employee {
   
    int _age;
    String _name;
   
    public Employee(String Name,int Age)
    {
        this._name=Name;
        this._age=Age;
    }
   
    public String getName()
    {
        return this._name;
    }
   
    public int getAge()
    {
        return this._age;
    }
   
    public void setName(String Name)
    {
        this._name=Name;
    }
    public void setAge(int Age)
    {
        this._age=Age;
    }
   

}

Activity to populate table values in Expandable List View


This Activity disaplays Expandable Listview that displays populated table values.

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.widget.ExpandableListAdapter;
import android.widget.SimpleExpandableListAdapter;

public class sample extends ExpandableListActivity {
    private static final String NAME = "NAME";
    DBHelper helper;
    List dispData;
    Iterator it;
   
    String[] data;
    String[] name;
    int[] age;
    private ExpandableListAdapter mAdapter;
   
      
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        helper = new DBHelper(getApplicationContext());
        dispData=helper.viewTable();

        name=new String[dispData.size()];
       
        name=(String[])dispData.get(0);
        age=(int[]) dispData.get(1);
        for(int i=0;i<name.length;i++)
        {
            System.out.println("New data :"+name[i]);
        }
       
       /* data=new String[dispData.size()];
        it=dispData.iterator();
        i=0;
        while(it.hasNext()) {
            String value=it.next().toString();
            data[i]=value;
            i++;
        }*/
      
           
        List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();
        List<List<Map<String, String>>> childData = new ArrayList<List<Map<String, String>>>();
      
        for (int i = 0; i < name.length; i++) {
            Map<String, String> curGroupMap = new HashMap<String, String>();
            groupData.add(curGroupMap);
            curGroupMap.put(NAME,"" +name[i]);
        
            List<Map<String, String>> children = new ArrayList<Map<String, String>>();
         
                Map<String, String> curChildMap = new HashMap<String, String>();
                children.add(curChildMap);
                curChildMap.put(NAME,"" +age[i]);
                                 
            childData.add(children);
          
        }
       
        // Set up our adapter
        mAdapter = new SimpleExpandableListAdapter(
                this,
                groupData,
                android.R.layout.simple_expandable_list_item_1,
                new String[] { NAME },
                new int[] { android.R.id.text1 },
                childData,
                android.R.layout.simple_expandable_list_item_2,
                new String[] { NAME },
                new int[] { android.R.id.text1 }
                );
        setListAdapter(mAdapter);
    }
    }

Gallery Viewer

This is Android Code which I designed recently. Using Gallery View in android we can able to view photos and here is what I done. I developed this using Android 2.2 with eclipse Helios. 

Step 1: Designing XML

I am using a legacy linear layout which contains gallery to load images and image view to view images.

This is how main.xml looks:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/LinearLayout01"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical">
    <Gallery xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/examplegallery"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
    <ImageView android:id="@+id/ImageView01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>
</LinearLayout>

Step 2: Adding Gallery Theme

Add the following xml in your application in /res/values/ folder and name as attributes.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="GalleryTheme">
        <attr name="android:galleryItemBackground" />
    </declare-styleable>
</resources>

Step 3: Adding Images

Add Your Desired Images In /res/drawable folder which contains drawable-hdpi, drawable-mdpi and drawable-ldpi folders refer http://developer.android.com/guide/practices/ui_guidelines/icon_design.html for desinging the icons.

Step 4: The Final Code

Create Objects for Image View and Gallery

protected Gallery gallery;
protected ImageView imgView;

Create Image Array and Context

protected Context con=this;
    public Integer[] imageId={R.drawable.icon,R.drawable.sample_0,
            R.drawable.sample_1,R.drawable.sample_2,
            R.drawable.sample_3,R.drawable.sample_4,
            R.drawable.sample_5,R.drawable.sample_6,
            R.drawable.sample_7};

in Oncreate method of activity class initialize the view for galley and image view and set the source drivers (Adapters) for gallery and invoke the Onclick listener for the items in gallery 

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        gallery=(Gallery) findViewById(R.id.examplegallery);
        imgView=(ImageView) findViewById(R.id.ImageView01);
        gallery.setAdapter(new ImageAdapter(con));
        gallery.setOnItemClickListener(listener);
    }

Create a new class ImageAdpater for setting Image view which extends the BaseAdapter

public class ImageAdapter extends BaseAdapter {

        int galleryBackGround;
       
        public ImageAdapter(Context c) {
            con=c;
            TypedArray tArray=obtainStyledAttributes(R.styleable.GalleryTheme);
            galleryBackGround=tArray.getResourceId(R.styleable.GalleryTheme_android_galleryItemBackground,0);
            tArray.recycle();
        }
       
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return imageId.length;
        }

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

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

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            ImageView iv=new ImageView(con);
            iv.setImageResource(imageId[position]);
            iv.setLayoutParams(new Gallery.LayoutParams(77, 77));
            iv.setScaleType(ImageView.ScaleType.FIT_XY);
            iv.setBackgroundResource(galleryBackGround);
           
            return iv;
        }
       
    }

Then finally to view Image implement the OnItemClickListener as follows:

protected OnItemClickListener listener=new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View v, int position,
                long id) {
            // TODO Auto-generated method stub
            Toast.makeText(getApplicationContext(), "You selected picture "+position, Toast.LENGTH_LONG).show();
            imgView.setScaleType(ImageView.ScaleType.FIT_XY);
            Log.d("Left padding ", ""+imgView.getPaddingLeft());
            Log.d("right padding ", ""+imgView.getPaddingRight());
            Log.d("top padding ", ""+imgView.getPaddingTop());
            Log.d("bottom padding ", ""+imgView.getPaddingBottom());
            imgView.setImageResource(imageId[position]);
            imgView.setPadding(30, 10, 30, 10);
        }
    };