Many a times you need to filter or search data. That data may be contained in an SQLite database.
There are two ways to do that:
The second option is the faster one since we take advantage of the heavily optimized SQL databases.
We use the second approach in this tutorial.
But first we need to insert data into database and populate the ListView. So we do all those.
We use the SearchView as our search input widget.
Let's go.
First create an empty project in android studio. Go here for more details.
We add some support libraries inside the app level build.gradle:
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.3.0'
compile 'com.android.support:design:23.3.0'
compile 'com.android.support:cardview-v7:23.3.0'
}
User interfaces are typically created in android using XML layouts as opposed by direct java coding.
This is an example fo declarative programming. Here's the autogenerated code for activity_main.xml
file:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.tutorials.hp.sqlitefilterlistview.MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<include layout="@layout/content_main" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="@dimen/fab_margin"
android:src="@android:drawable/ic_dialog_email" />
</android.support.design.widget.CoordinatorLayout>
This layout gets included in your activity_main.xml. You define your UI widgets right here. We will have a searchview for searching right on top our Listview which is our AdapterView.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
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"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.tutorials.hp.sqlitefilterlistview.MainActivity"
tools:showIn="@layout/activity_main">
<android.support.v7.widget.SearchView
android:id="@+id/sv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:queryHint="Search.."
></android.support.v7.widget.SearchView>
<ListView
android:id="@+id/lv"
android:layout_below="@+id/sv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
></ListView>
</RelativeLayout>
This layout will be used to construct our input dialog. That dialog is actually our data entry form.
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="500dp"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_margin="1dp"
card_view:cardCornerRadius="10dp"
card_view:cardElevation="5dp"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:orientation="vertical"
android:layout_height="match_parent">
<android.support.design.widget.TextInputLayout
android:id="@+id/nameLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<EditText
android:id="@+id/nameEditTxt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:singleLine="true"
android:hint= "Name" />
</android.support.design.widget.TextInputLayout>
<Button android:id="@+id/saveBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Save"
android:clickable="true"
android:background="@color/colorAccent"
android:layout_marginTop="40dp"
android:textColor="@android:color/white"/>
<Button android:id="@+id/retrieveBtn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Retrieve"
android:clickable="true"
android:background="@color/colorAccent"
android:layout_marginTop="40dp"
android:textColor="@android:color/white"/>
</LinearLayout>
</android.support.v7.widget.CardView>
This layout will be used to construct our ListView View items.
It's our custom row template.
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_margin="5dp"
card_view:cardCornerRadius="10dp"
card_view:cardElevation="5dp"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Name"
android:id="@+id/nameTxt"
android:padding="10dp"
android:layout_alignParentTop="true"
/>
</RelativeLayout>
</android.support.v7.widget.CardView>
Let's now jump to java.
This is our POJO class. It defines for us the properties for a single planet.
We will be saving planet objects into our sqlite database. As you can see a single planet will have a name and an id as properties.
package com.tutorials.hp.sqlitefilterlistview.mDataObject;
public class Planet {
String name;
int id;
public Planet() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
These are classes helping us work with SQLite database.
This class will hold for us our sqlite database constants, as the name suggests.
These constants include sqlite database name, database version, sqlite tabe name, table column names, database table creation and deletion statements.
All of these are defined as simple string constants.
package com.tutorials.hp.sqlitefilterlistview.mDataBase;
public class Constants {
//COLUMNS
static final String ROW_ID="id";
static final String NAME="name";
//DB
static final String DB_NAME="ii_DB";
static final String TB_NAME="ii_TB";
static final int DB_VERSION=1;
//CREATE TB
static final String CREATE_TB="CREATE TABLE ii_TB(id INTEGER PRIMARY KEY AUTOINCREMENT,"
+ "name TEXT NOT NULL);";
//DROP TB
static final String DROP_TB="DROP TABLE IF EXISTS "+TB_NAME;
}
This is our SQLiteHelper class. This class helps in database table creation and upgade.
package com.tutorials.hp.sqlitefilterlistview.mDataBase;
import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DBHelper extends SQLiteOpenHelper {
public DBHelper(Context context) {
super(context, Constants.DB_NAME, null, Constants.DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
try
{
db.execSQL(Constants.CREATE_TB);
}catch (SQLException e)
{
e.printStackTrace();
}
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL(Constants.DROP_TB);
onCreate(db);
}
}
This is our database adapter class.
It is in this class where we will perform our CRUD and data retrieval including searching SQlite data.
First a database connection is opened, data is inserted to sqlite, data can be retrieved or searched by passing in search term.
Finally database connection is closed.
We start by defining three instance fields:
Then our constrructor will receive a context object via the constructor. That Context will be required by our DBHelper class.
Opening our database is easy, we invoke the getWritableDatabase()
, receiving a SQLiteDatabase object which we hold in our db
variable.
db=helper.getWritableDatabase();
As for Closing we simply use the close()
method:
helper.close();
To insert first we need a ContentValues object.
ContentValues cv=new ContentValues();
Then simply use it's put()
method to hold our data. There we pass a key and value. The key is the database column name while the value is the data to be inserted:
cv.put(Constants.NAME, name);
Then to insert we use the `insert()` method of the `SQLiteDatabase` class
```java
db.insert(Constants.TB_NAME, Constants.ROW_ID, cv);
package com.tutorials.hp.sqlitefilterlistview.mDataBase;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.provider.SyncStateContract;
public class DBAdapter {
Context c;
SQLiteDatabase db;
DBHelper helper;
public DBAdapter(Context c) {
this.c = c;
helper=new DBHelper(c);
}
//OPEN DB
public void openDB()
{
try
{
db=helper.getWritableDatabase();
}catch (SQLException e)
{
e.printStackTrace();
}
}
//CLOSE
public void closeDB()
{
try
{
helper.close();
}catch (SQLException e)
{
e.printStackTrace();
}
}
//INSERT DATA
public boolean add(String name)
{
try
{
ContentValues cv=new ContentValues();
cv.put(Constants.NAME, name);
db.insert(Constants.TB_NAME, Constants.ROW_ID, cv);
return true;
}catch (SQLException e)
{
e.printStackTrace();
}
return false;
}
//RETRIEVE DATA AND FILTER
public Cursor retrieve(String searchTerm)
{
String[] columns={Constants.ROW_ID,Constants.NAME};
Cursor c=null;
if(searchTerm != null && searchTerm.length()>0)
{
String sql="SELECT * FROM "+Constants.TB_NAME+" WHERE "+Constants.NAME+" LIKE '%"+searchTerm+"%'";
c=db.rawQuery(sql,null);
return c;
}
c=db.query(Constants.TB_NAME,columns,null,null,null,null,null);
return c;
}
}
Our ListView Adapter class. This class is required as we are working with a custom listview.
First we have to make sure we have defined a model
layout.
That model.xml
layout will be inflated here and used as the listView's viewitem.
Data from SQLite is then bound to the ListView.
package com.tutorials.hp.sqlitefilterlistview.mListView;
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 android.widget.Toast;
import com.tutorials.hp.sqlitefilterlistview.R;
import com.tutorials.hp.sqlitefilterlistview.mDataObject.Planet;
import java.util.ArrayList;
public class CustomAdapter extends BaseAdapter {
Context c;
ArrayList<Planet> planets;
LayoutInflater inflater;
public CustomAdapter(Context c, ArrayList<Planet> planets) {
this.c = c;
this.planets = planets;
}
@Override
public int getCount() {
return planets.size();
}
@Override
public Object getItem(int position) {
return planets.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if(inflater==null)
{
inflater= (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
if(convertView==null)
{
convertView=inflater.inflate(R.layout.model,parent,false);
}
TextView nameTxt= (TextView) convertView.findViewById(R.id.nameTxt);
nameTxt.setText(planets.get(position).getName());
final int pos=position;
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(c,planets.get(pos).getName(),Toast.LENGTH_SHORT).show();
}
});
return convertView;
}
}
This is our main and only activity. Activities represent user interface in android and so does this.
We define a searchview for searching data and listview for showing data.
Also a dialog that will be used as our data entry form.
package com.tutorials.hp.sqlitefilterlistview;
import android.app.Dialog;
import android.database.Cursor;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.SearchView;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import com.tutorials.hp.sqlitefilterlistview.mDataBase.DBAdapter;
import com.tutorials.hp.sqlitefilterlistview.mDataObject.Planet;
import com.tutorials.hp.sqlitefilterlistview.mListView.CustomAdapter;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
ListView lv;
SearchView sv;
EditText nameEditText;
Button saveBtn,retrieveBtn;
CustomAdapter adapter;
ArrayList<Planet> planets=new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
lv= (ListView) findViewById(R.id.lv);
sv= (SearchView) findViewById(R.id.sv);
adapter=new CustomAdapter(this,planets);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
displayDialog();
}
});
sv.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextSubmit(String query) {
return false;
}
@Override
public boolean onQueryTextChange(String newText) {
getPlanets(newText);
return false;
}
});
}
private void displayDialog()
{
Dialog d=new Dialog(this);
d.setTitle("SQLite Database");
d.setContentView(R.layout.dialog_layout);
nameEditText= (EditText) d.findViewById(R.id.nameEditTxt);
saveBtn= (Button) d.findViewById(R.id.saveBtn);
retrieveBtn= (Button) d.findViewById(R.id.retrieveBtn);
saveBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
save(nameEditText.getText().toString());
}
});
retrieveBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getPlanets(null);
}
});
d.show();
}
private void save(String name)
{
DBAdapter db=new DBAdapter(this);
db.openDB();
if(db.add(name))
{
nameEditText.setText("");
}else {
Toast.makeText(this,"Unable To Save",Toast.LENGTH_SHORT).show();
}
db.closeDB();
this.getPlanets(null);
}
private void getPlanets(String searchTerm)
{
planets.clear();
DBAdapter db=new DBAdapter(this);
db.openDB();
Planet p=null;
Cursor c=db.retrieve(searchTerm);
while (c.moveToNext())
{
int id=c.getInt(0);
String name=c.getString(1);
p=new Planet();
p.setId(id);
p.setName(name);
planets.add(p);
}
db.closeDB();
lv.setAdapter(adapter);
}
}
Here are the resources related to this tutorial.
No. | Location | Link |
---|---|---|
1. | GitHub | Direct Download) |
2. | GitHub | Browse |
3. | YouTube | Video Tutorial |
4. | YouTube | Our YouTube Channel |