Android MySQL – Select Multiple Columns and Fill Custom ListView

Android MySQL – Select Multiple Columns and Fill Custom ListView Tutorial

How to select multiple columns from mysql database and populate a custom listview with multiple textviews.

Overview

Welcome. In this class we are going to look at MySQL database. How to connect to MySQL, retrieve multiple columns and rows from a given database table and bind them to a custom ListView.

That ListView will have several fields, each representing a given record column from our mysql database table.

These fields will include:

• ID.
• Name.
• Propellant.
• Description.

Our application will have the following classes:

Tools Used

These are the tools we used to create the project:

1. Language : Java.
2. Platform : Android.
3. IDE : Android Studio.
4. OS : Windows 8.1

Let’s go.

1. PHP Code

Here’s our PHP Code to select multiple columns data from our mysql database and return it in json format.
Am using Wamp: C:wampwwwandroidspacecraft_select.php.

<?php

$host='127.0.0.1';
$username='root';
$pwd='';
$db="spacecraftDB";

$con=mysqli_connect($host,$username,$pwd,$db) or die('Unable to connect');

if(mysqli_connect_error($con))
{
    echo "Failed to Connect to Database ".mysqli_connect_error();
}

$sql="SELECT * FROM spacecraftTB";

$result=mysqli_query($con,$sql);
if($result)
{
    while($row=mysqli_fetch_array($result))
    {
        $flag[]=$row;
    }

    print(json_encode($flag));

}

mysqli_close($con);

?>

2. Setup

(a). Create Basic Activity Project

1. First create a new project in android studio. Go to File –> New Project.

(b). Project Structure

Here’s our project structure:

(c). Build.Gradle

Our app level(app folder) build.gradle.

AndroidStudio allows us to add our application dependencies right here using compile statements.

So we add our dependencies here. You may use later versions of the dependencies.

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:26.+'
    compile 'com.android.support:design:26.+'
    compile 'com.android.support:cardview-v7:26.+'

}

(d). AndroidManifest.xml

We add internet permission here.

<?xml version="1.0" encoding="utf-8"?>
<manifest 
    package="com.tutorials.hp.mdmysqlselect">

    <uses-permission android_name="android.permission.INTERNET"/>
    ...
</manifest>

3. Create User Interface

User interfaces are typically created in android using XML layouts as opposed to direct java coding.

Here are our layouts for this project:

(a). activity_main.xml

• This layout gets inflated to MainActivity user interface.
• It includes the content_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_fitsSystemWindows="true"
    tools_context="com.tutorials.hp.mdmysqlselect.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>

(b). content_main.xml

This layout gets included in your activity_main.xml.
We define our UI widgets here.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    
    
    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.mdmysqlselect.MainActivity"
    tools_showIn="@layout/activity_main">

    <ListView
        android_id="@+id/lv"
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
         />
</RelativeLayout>

(c). model.xml

This is our custom row layout. Our model layout.

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 
    android_orientation="horizontal" android_layout_width="match_parent"
    
    android_layout_margin="10dp"
    card_view_cardCornerRadius="5dp"
    card_view_cardElevation="5dp"

    android_layout_height="150dp">

    <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_textColor="@color/colorAccent"

            android_layout_alignParentLeft="true"
             />

        <TextView
            android_layout_width="wrap_content"
            android_layout_height="wrap_content"
            android_textAppearance="?android:attr/textAppearanceLarge"
            android_text="Description....................."
            android_id="@+id/descTxt"
            android_padding="10dp"
            android_layout_below="@+id/nameTxt"
            android_layout_alignParentLeft="true"

            />

        <TextView
            android_layout_width="wrap_content"
            android_layout_height="wrap_content"
            android_textAppearance="?android:attr/textAppearanceLarge"
            android_text="Propellant"
            android_id="@+id/propellantTxt"
            android_textColor="@color/colorPrimary"
            android_padding="10dp"
            android_layout_alignParentRight="true"
            />

    </RelativeLayout>
</android.support.v7.widget.CardView>

4. Java Code

(a). Spacecraft.java

Android is normally written in Java programming language. Java classes are normally organized in packages. This class will have the com.tutorials.hp.mdmysqlselect.mDataObject package.

This class is a public class and represents a single spacecraft for us.

The class will have the following instance fields:

1. Id – spacecraft id.
2. Name – spacecraft name.
3. Propellant – spacecraft propellant.
4. description – spacecraft description.

We create the getters and setters of these instance fields.

package com.tutorials.hp.mdmysqlselect.mDataObject;

public class Spacecraft {
    int id;
    String name,propellant,description;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPropellant() {
        return propellant;
    }

    public void setPropellant(String propellant) {
        this.propellant = propellant;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}

(b). CustomAdapter.java

This class will be deriving from android.widget.BaseAdapter. This class is public class.

This class will maintain a couple of instance fields:

    Context c;
    ArrayList<Spacecraft> spacecrafts;
    LayoutInflater inflater;

1. Context object – Will assist in inflation of our model layout.
2. ArrayList of generic type Spacecraft class.
3. LayoutInflater object to inflate our model.xml layout.

The constructor of this class will take in a Context object and an ArrayList of spacecrafts objects.

Then inside the Constructor we assign those objects to their respective class instance fields that we had defined.

this.c = c;
this.spacecrafts = spacecrafts;

We then initialiaze our LayoutInflater class: inflater= (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE) assigning to LayoutInflater class.

LayoutInflater instance will later allow us inflate our XML layout into view object.

After deriving from baseadapter, we will be forced to implement a couple of abstract methods.
These include :

1. getCount() – return the number of spacecrafts to bind to our ListView.
2. getItem()– get a single spacecraft object.
3. getView() – inflate the model.xml layout and return it as a view object.

package com.tutorials.hp.mdmysqlselect.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.mdmysqlselect.R;
import com.tutorials.hp.mdmysqlselect.mDataObject.Spacecraft;

import java.util.ArrayList;

public class CustomAdapter extends BaseAdapter {

    Context c;
    ArrayList<Spacecraft> spacecrafts;
    LayoutInflater inflater;

    public CustomAdapter(Context c, ArrayList<Spacecraft> spacecrafts) {
        this.c = c;
        this.spacecrafts = spacecrafts;

        //INITIALIE
        inflater= (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
        return spacecrafts.size();
    }

    @Override
    public Object getItem(int position) {
        return spacecrafts.get(position);
    }

    @Override
    public long getItemId(int position) {
        return spacecrafts.get(position).getId();
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        if(convertView==null)
        {
            convertView=inflater.inflate(R.layout.model,parent,false);
        }

        TextView nameTxt= (TextView) convertView.findViewById(R.id.nameTxt);
        TextView propellantTxt= (TextView) convertView.findViewById(R.id.propellantTxt);
        TextView descTxt= (TextView) convertView.findViewById(R.id.descTxt);

        nameTxt.setText(spacecrafts.get(position).getName());
        propellantTxt.setText(spacecrafts.get(position).getPropellant());
        descTxt.setText(spacecrafts.get(position).getDescription());

        //ITEM CLICKS
        convertView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(c,spacecrafts.get(position).getName(),Toast.LENGTH_SHORT).show();
            }
        });

        return convertView;
    }
}

(c). Connector.java

Next we come to our Connector.java class.

This class is a public class with one static method.

This method is our connect(..) method. This method will take a string object we are calling urlAddress to represent the URL string to our server side PHP script that will allow us fetch data from mysql database.

This method will return us a java.net.HttpURLConnection.

We’ll have a try-catch block, catching two exceptions :

1. java.net.MalformedURLException – Raised when a malformed URL is encountered.
2. java.io.IOException – Raised when an IO(Input Output) error has occured.

First we attempt to instantiate a java.net.URL passing in our URL address. URL stands for Uniform Resouce Locator and points to a Resource in a the World Wide Web. In this case that resource will be our php script.

url.openConnection() will return us a URLConnection object which represents the connection to the remote object referred to by the URL.

We cast that URLConnection to HttpURLConnection. HttpURLConnection is a url connection which supports HTTP specific features. It works with the HTTP protocol.

con.setRequestMethod() will set the HTTP Request method that we support. These can be :

1. GET.
2. POST.
3. PUT.
4. DELETE.
5. HEAD.
6. OPTIONS.

We use GET since we are fetching data.

con.setReadTimeout() will specify the timeout for reading our resouce while con.setConnectTimeout() indicates the timeout for our connection.

con.setDoInput() indicates that our connection supports input of data.

package com.tutorials.hp.mdmysqlselect.mMySQL;

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

public class Connector {

    public static HttpURLConnection connect(String urlAddress)
    {
        try {
            URL url=new URL(urlAddress);
            HttpURLConnection con= (HttpURLConnection) url.openConnection();

            //SET PROPS
            con.setRequestMethod("GET");
            con.setConnectTimeout(20000);
            con.setReadTimeout(20000);
            con.setDoInput(true);

            return con;

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }

}

(d). DataParser.java

This is our Data Parser class.

package com.tutorials.hp.mdmysqlselect.mMySQL;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import com.tutorials.hp.mdmysqlselect.mDataObject.Spacecraft;
import com.tutorials.hp.mdmysqlselect.mListView.CustomAdapter;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;

public class DataParser  extends AsyncTask<Void,Void,Integer>{

    Context c;
    ListView lv;
    String jsonData;

    ProgressDialog pd;
    ArrayList<Spacecraft> spacecrafts=new ArrayList<>();

    public DataParser(Context c, ListView lv, String jsonData) {
        this.c = c;
        this.lv = lv;
        this.jsonData = jsonData;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        pd=new ProgressDialog(c);
        pd.setTitle("Parse");
        pd.setMessage("Parsing...Please wait");
        pd.show();
    }

    @Override
    protected Integer doInBackground(Void... params) {
        return this.parseData();
    }

    @Override
    protected void onPostExecute(Integer result) {
        super.onPostExecute(result);

        pd.dismiss();
        if(result==0)
        {
            Toast.makeText(c,"Unable to parse",Toast.LENGTH_SHORT).show();
        }else {
            //CALL ADAPTER TO BIND DATA
            CustomAdapter adapter=new CustomAdapter(c,spacecrafts);
            lv.setAdapter(adapter);
        }
    }

    private int parseData()
    {
        try {
            JSONArray ja=new JSONArray(jsonData);
            JSONObject jo=null;

            spacecrafts.clear();
            Spacecraft s=null;

            for(int i=0;i<ja.length();i++)
            {
                jo=ja.getJSONObject(i);

                int id=jo.getInt("id");
                String name=jo.getString("name");
                String propellant=jo.getString("propellant");
                String description=jo.getString("description");

                s=new Spacecraft();
                s.setId(id);
                s.setName(name);
                s.setPropellant(propellant);
                s.setDescription(description);

                spacecrafts.add(s);

            }

            return 1;

        } catch (JSONException e) {
            e.printStackTrace();
        }

        return 0;
    }
}

(e). Downloader.java

package com.tutorials.hp.mdmysqlselect.mMySQL;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.ListView;
import android.widget.Toast;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;

public class Downloader extends AsyncTask<Void,Void,String> {

    Context c;
    String urlAddress;
    ListView lv;

    ProgressDialog pd;

    public Downloader(Context c, String urlAddress, ListView lv) {
        this.c = c;
        this.urlAddress = urlAddress;
        this.lv = lv;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        pd=new ProgressDialog(c);
        pd.setTitle("Fetch");
        pd.setMessage("Fetching....Please wait");
        pd.show();
    }

    @Override
    protected String doInBackground(Void... params) {
        return this.downloadData();
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);

        pd.dismiss();

        if(s==null)
        {
            Toast.makeText(c,"Unsuccessfull,Null returned",Toast.LENGTH_SHORT).show();
        }else
        {
            //CALL DATA PARSER TO PARSE
            DataParser parser=new DataParser(c,lv,s);
            parser.execute();

        }

    }

    private String downloadData()
    {
        HttpURLConnection con=Connector.connect(urlAddress);
        if(con==null)
        {
            return null;
        }

        InputStream is=null;
        try {

            is=new BufferedInputStream(con.getInputStream());
            BufferedReader br=new BufferedReader(new InputStreamReader(is));

            String line=null;
            StringBuffer response=new StringBuffer();

            if(br != null)
            {
                while ((line=br.readLine()) != null)
                {
                    response.append(line+"n");
                }

                br.close();

            }else
            {
                return null;
            }

            return response.toString();

        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(is != null)
            {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return null;
    }
}

(f). MainActivity.java

package com.tutorials.hp.mdmysqlselect;

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.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;

import com.tutorials.hp.mdmysqlselect.mMySQL.Downloader;

public class MainActivity extends AppCompatActivity {

    //spacecraft_select.php is our pho code. It is contained in 
    //a folder called android. : C:wampwwwandroidspacecraft_select.php
    String urlAddress="http://10.0.2.2/android/spacecraft_select.php";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        final ListView lv= (ListView) findViewById(R.id.lv);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Downloader d=new Downloader(MainActivity.this,urlAddress,lv);
                d.execute();
            }
        });
    }

}

Android MySQL – ListView CheckBoxes – INSERT,SELECT,SHOW

This is an Android MySQ ListView with CheckBoxes tutorial. We want to see how to work with boolean text values. We save them into mysql and also retrieve them.

• We want to see how to work with Android PHP MySQL and Boolean values and strings.
• First we want to insert data to MySQL database.
• The data shall be from a material edittext,a spinner and a checkbox.
• The user types his favorite spacecraft name in the edittext.Then selects the spacecraft’s propellant from a spinner.
• He then selects if the technology exists yet or not in the checkbox.
• We shall actually be mapping integers to boolean and vice versa since MySQL doesn’t have a native boolean data type.
• Our adapterview is ListView.It has checkboxes to hold boolean values from MySQL database.

Video Tutorial(ProgrammingWizards TV Channel)

Well we have a video tutorial as an alternative to this. If you prefer tutorials like this one then it would be good you subscribe to our YouTube channel.

Basically we have a TV for programming where do daily tutorials especially android.

Android MySQL ListView CheckBoxes Insert, Select Show Example

Let’s look at our example:

MySQL Table

Here’s our mysql table structure:

Project Structure

Here’s our project structure.

1. PHP Code

Here are our php code. Place them in the same folder.

(a) Constants.php

<?php

class Constants
{
    //DATABASE DETAILS
    static $DB_SERVER="localhost";
    static $DB_NAME="galileoDB";
    static $USERNAME="root";
    static $PASSWORD="";
    const TB_NAME="galileoTB";
    //STATEMENTS
    static $SQL_SELECT_ALL="SELECT * FROM galileoTB";
}

(b) CRUD.php

<?php

require_once("/DBAdapter.php");
if($_POST['action']=="save"){

         $dbAdapter=new DBAdapter();
         $name=$_POST['name'];
         $propellant=$_POST['propellant'];
         $technologyexists=$_POST['technologyexists'];
        $dbAdapter->insert(array($name,$propellant,$technologyexists));
}
else if($_POST['action']=="update")
{
         $dbAdapter=new DBAdapter();
         $id=$_POST['id'];
         $name=$_POST['name'];
         $propellant=$_POST['propellant'];
         $technologyexists=$_POST['technologyexists'];
        $dbAdapter->update($id,array($name,$propellant,$technologyexists));

}
else if($_POST['action']=="delete")
{
         $dbAdapter=new DBAdapter();
         $id=$_POST['id'];

        $dbAdapter->delete($id);
}
?>

(c) DBAdapter.php

<?php

require_once("/Constants.php");
class DBAdapter
{
/*******************************************************************************************************************************************/
/*
   1.CONNECT TO DATABASE.
   2. RETURN CONNECTION OBJECT
*/
    public function connect()
    {

       $con=mysqli_connect(Constants::$DB_SERVER,Constants::$USERNAME,Constants::$PASSWORD,Constants::$DB_NAME);
        if(mysqli_connect_error(!$con))
        {
           // echo "Unable To Connect";
            return null;
        }else
        {

            return $con;
        }
    }
    /*******************************************************************************************************************************************/
/*
   1.INSERT SPACECRAFT INTO DATABASE
 */
    public function insert($s)
    {
        // INSERT
        $con=$this->connect();

        if($con != null)
        {
            $sql="INSERT INTO galileoTB(name,propellant,technologyexists) VALUES('$s[0]','$s[1]','$s[2]')";
            try
            {
                $result=mysqli_query($con,$sql);
                if($result)
                {
                    print(json_encode(array("Success")));
                }else
                {
                    print(json_encode(array("Unsuccessfull")));
                }
            }catch (Exception $e)
            {
               print(json_encode(array("PHP EXCEPTION : CAN'T SAVE TO MYSQL. "+$e->getMessage())));
            }
        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
        mysqli_close($con);
    }
/*******************************************************************************************************************************************/
/*
   1.SELECT FROM DATABASE.
*/
    public function select()
    {
       $con=$this->connect();
        if($con != null)
        {
            $retrieved=mysqli_query($con,Constants::$SQL_SELECT_ALL);
            if($retrieved)
            {
                while($row=mysqli_fetch_array($retrieved))
                {

                   // echo $row["name"] ,"    t | ",$row["propellant"],"</br>";
                   $spacecrafts[]=$row;
                }
                print(json_encode($spacecrafts));
            }else
            {
                 print(json_encode(array("PHP EXCEPTION : CAN'T RETRIEVE FROM MYSQL. ")));
            }
        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
        mysqli_close($con);
    }
/*******************************************************************************************************************************************/
/*
   1.UPDATE  DATABASE.

*/
    public function update($id, $s)
    {
        // UPDATE
        $con=$this->connect();

        if($con != null)
        {
            $sql="UPDATE galileoTB SET name='$s[0]',propellant='$s[1]',technologyexists='$s[2]' WHERE id='$id'";
            try
            {
                $result=mysqli_query($con,$sql);
                if($result)
                {
                    print(json_encode(array("Successfully Updated")));
                }else
                {
                    print(json_encode(array("Not Successfully Updated")));
                }
            }catch (Exception $e)
            {
                 print(json_encode(array("PHP EXCEPTION : CAN'T UPDATE INTO MYSQL. "+$e->getMessage())));
            }
        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
        mysqli_close($con);
    }
/*******************************************************************************************************************************************/
/*
   1.DELETE SPACECRAFT FROM DATABASE.

*/
    public function delete($id)
    {
        $con=$this->connect();

        if($con != null)
        {
//            $name=$_POST['Name'];
//            $pos=$_POST['Position'];
//            $team=$_POST['Team'];
            $sql="DELETE FROM galileoTB WHERE id='$id'";
            try
            {
                $result=mysqli_query($con,$sql);
                if($result)
                {
                    print(json_encode(array("Successfully Deleted")));
                }else
                {
                    print(json_encode(array("Not Successfully Deleted")));
                }
            }catch (Exception $e)
            {
                print(json_encode(array("PHP EXCEPTION : CAN'T DELETE FROM MYSQL. "+$e->getMessage())));
            }
        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
        mysqli_close($con);
    }

}

(d) Index.php

<?php

require_once("/DBAdapter.php");
    $dbAdapter=new DBAdapter();
    $dbAdapter->select();
?>

2. Gradle Scripts

Here are our gradle scripts in our build.gradle file(s).

(a). build.gradle(app)

Here’s our app level build.gradle file. We have the dependencies DSL where we add our dependencies.

This file is called app level build.gradle since it’s located in the app folder of the project.

If you are using Android Studio version 3 and above use implementation keyword while if you are using a version less than 3 then still use the compile keyword.

Once you’ve modified this build.gradle file you have to sync your project. Android Studio will indeed prompt you to do so.

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:24.2.0'
    compile 'com.android.support:design:24.2.0'
    compile 'com.android.support:cardview-v7:24.2.0'
    compile 'com.amitshekhar.android:android-networking:0.2.0'
}

[notice]
We are using Fast Android Networking Library as our HTTP Client. You may use newer versions.
[/notice]

3. Resoources.

Android platform provides a powerful and flexible way of adding static content as a resource.

These static content will also be packaged into the APK file. The static content will be stored either as a resource or as an asset.

Resources belong to a given type. These types can be:

1. Drawable.
2. Layout.
3. Value.

Let’s start by looking at the layout resources

(a). model.xml

Our row model layout.

?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 
    android_orientation="horizontal" android_layout_width="match_parent"
    
    android_layout_margin="10dp"
    card_view_cardCornerRadius="5dp"
    card_view_cardElevation="5dp"
    android_layout_height="200dp">

        <LinearLayout
            android_orientation="vertical"
            android_layout_width="match_parent"
            android_layout_height="match_parent">

            <TextView
                android_layout_width="match_parent"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceLarge"
                android_text="Name"
                android_id="@+id/nameTxt"
                android_padding="10dp"
                android_textColor="@color/colorAccent"
                android_textStyle="bold"
                android_layout_alignParentLeft="true"
                />

            <TextView
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textAppearance="?android:attr/textAppearanceLarge"
                android_text="Propellant....................."
                android_id="@+id/txtPropellant"
                android_padding="10dp"
                android_layout_alignParentLeft="true"
                />
            <CheckBox
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textSize="25dp"
                android_id="@+id/chkTechExists"
                android_checked="true" />

    </LinearLayout>

</android.support.v7.widget.CardView>

(b). content_main.xml

Our content_main layout. This layout is being inserted into our activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    
    
    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.mysqllistviewbool.MainActivity"
    tools_showIn="@layout/activity_main">
    <LinearLayout
        android_orientation="vertical"
        android_layout_width="match_parent"
        android_layout_height="wrap_content">

        <android.support.design.widget.TextInputEditText
            android_id="@+id/nameTxt"
            android_hint="Name"
            android_layout_width="match_parent"
            android_layout_height="wrap_content"
            android_textStyle="bold"
            android_textSize="25dp"
            android_enabled="true"
            android_focusable="true" />

        <LinearLayout
            android_orientation="horizontal"
            android_padding="5dp"
            android_layout_width="match_parent"
            android_layout_height="wrap_content">
            <TextView
                android_textSize="25dp"
                android_text="Propellant"
                android_textStyle="bold"
                android_layout_width="250dp"
                android_layout_height="wrap_content" />
            <Spinner
                android_id="@+id/sp"
                android_textSize="25dp"
                android_textStyle="bold"
                android_layout_width="wrap_content"
                android_layout_height="wrap_content" />
        </LinearLayout>

        <LinearLayout
            android_orientation="horizontal"
            android_padding="5dp"
            android_layout_width="match_parent"
            android_layout_height="wrap_content">
            <TextView
                android_textSize="25dp"
                android_text="Technology Exists ??"
                android_textStyle="bold"
                android_layout_width="250dp"
                android_layout_height="wrap_content" />
            <CheckBox
                android_layout_width="wrap_content"
                android_layout_height="wrap_content"
                android_textSize="25dp"
                android_id="@+id/techExists"
                android_checked="true" />
        </LinearLayout>

        <RelativeLayout
            android_orientation="horizontal"
            android_layout_width="match_parent"
            android_layout_height="wrap_content">

            <Button android_id="@+id/addBtn"
                android_layout_width="wrap_content"
                android_layout_height="60dp"
                android_text="Save"
                android_clickable="true"
                android_padding="5dp"
                android_background="#009968"
                android_textColor="@android:color/white"
                android_textStyle="bold"
                android_textSize="20dp" />

            <Button android_id="@+id/refreshBtn"
                android_layout_width="wrap_content"
                android_layout_height="60dp"
                android_text="Retrieve"
                android_padding="5dp"
                android_clickable="true"
                android_background="#f38630"
                android_textColor="@android:color/white"
                android_layout_alignParentTop="true"
                android_layout_alignParentRight="true"
                android_layout_alignParentEnd="true"
                android_textStyle="bold"
                android_textSize="20dp" />

        </RelativeLayout>

        <ListView
            android_id="@+id/lv"
            android_layout_width="match_parent"
            android_layout_height="wrap_content">

        </ListView>

    </LinearLayout>
</RelativeLayout>

(c). activity_main.xml

Our activity_main layout.

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    
    
    android_layout_width="match_parent"
    android_layout_height="match_parent"
    android_fitsSystemWindows="true"
    tools_context="com.tutorials.hp.mysqllistviewbool.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>

(a). Spacecraft.java

First we have a data object POJO class as below.

package com.tutorials.hp.mysqllistviewbool.mModel;

public class Spacecraft {
    /*
    INSTANCE FIELDS
     */
    private int id;
    private String name;
    private String propellant;
    private int technologyExists;

    /*
    GETTERS AND SETTERS
     */
    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPropellant() {
        return propellant;
    }

    public void setPropellant(String propellant) {
        this.propellant = propellant;
    }

    public int getTechnologyExists() {
        return technologyExists;
    }

    public void setTechnologyExists(int technologyExists) {
        this.technologyExists = technologyExists;
    }
    /*
    TOSTRING
     */
    @Override
    public String toString() {
        return name;
    }
}

(b). MySQLClient.java

Our most important class is our MySQL Client class.It is responsible fro bothh connecting,inserting and retrieving data and handling errors appropriately.We are using the easy to use yet efficient Android Networking Library.

package com.tutorials.hp.mysqllistviewbool.mMySQL;

import android.content.Context;
import android.view.View;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Spinner;
import android.widget.Toast;

import com.androidnetworking.AndroidNetworking;
import com.androidnetworking.common.Priority;
import com.androidnetworking.error.ANError;
import com.androidnetworking.interfaces.JSONArrayRequestListener;
import com.tutorials.hp.mysqllistviewbool.mAdapter.ListViewAdapter;
import com.tutorials.hp.mysqllistviewbool.mModel.Spacecraft;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;

public class MySQLClient {

    //SAVE/RETRIEVE URLS
    private static final String DATA_INSERT_URL="http://10.0.2.2/android/Aristotle/crud.php";
    private static final String DATA_RETRIEVE_URL="http://10.0.2.2/android/Aristotle/index.php";

    //INSTANCE FIELDS
    private final Context c;
    private ListViewAdapter adapter ;

    public MySQLClient(Context c) {
        this.c = c;

    }
    /*
   SAVE/INSERT
    */
    public void add(Spacecraft s, final View...inputViews)
    {
        if(s==null)
        {
            Toast.makeText(c, "No Data To Save", Toast.LENGTH_SHORT).show();
        }
        else
        {
            AndroidNetworking.post(DATA_INSERT_URL)

                    .addBodyParameter("action","save")
                    .addBodyParameter("name",s.getName())
                    .addBodyParameter("propellant",s.getPropellant())
                    .addBodyParameter("technologyexists",String.valueOf(s.getTechnologyExists()))
                    .setTag("TAG_ADD")
                    .build()
                    .getAsJSONArray(new JSONArrayRequestListener() {
                        @Override
                        public void onResponse(JSONArray response) {

                            if(response != null)
                                try {
                                    //SHOW RESPONSE FROM SERVER
                                    String responseString = response.get(0).toString();
                                    Toast.makeText(c, "PHP SERVER RESPONSE : " + responseString, Toast.LENGTH_SHORT).show();

                                    if (responseString.equalsIgnoreCase("Success")) {
                                        //RESET VIEWS
                                        EditText nameTxt = (EditText) inputViews[0];
                                        Spinner spPropellant = (Spinner) inputViews[1];

                                        nameTxt.setText("");
                                        spPropellant.setSelection(0);
                                    }else
                                    {
                                        Toast.makeText(c, "PHP WASN'T SUCCESSFUL. ", Toast.LENGTH_SHORT).show();

                                    }

                                } catch (JSONException e) {
                                    e.printStackTrace();
                                    Toast.makeText(c, "GOOD RESPONSE BUT JAVA CAN'T PARSE JSON IT RECEIVED : "+e.getMessage(), Toast.LENGTH_SHORT).show();
                                }

                        }

                        //ERROR
                        @Override
                        public void onError(ANError anError) {
                            Toast.makeText(c, "UNSUCCESSFUL :  ERROR IS : "+anError.getMessage(), Toast.LENGTH_SHORT).show();
                        }

                    });

        }
    }

    /*
    RETRIEVE/SELECT/REFRESH
     */
    public void retrieve(final ListView lv)
    {
        final ArrayList<Spacecraft> spacecrafts = new ArrayList<>();

        AndroidNetworking.get(DATA_RETRIEVE_URL)
                .setPriority(Priority.HIGH)
                .build()
                .getAsJSONArray(new JSONArrayRequestListener() {
                    @Override
                    public void onResponse(JSONArray response) {
                        JSONObject jo;
                        Spacecraft s;
                        try
                        {
                            for(int i=0;i<response.length();i++)
                            {
                                jo=response.getJSONObject(i);

                                int id=jo.getInt("id");
                                String name=jo.getString("name");
                                String propellant=jo.getString("propellant");
                                String techExists=jo.getString("technologyexists");

                                s=new Spacecraft();
                                s.setId(id);
                                s.setName(name);
                                s.setPropellant(propellant);
                                s.setTechnologyExists(techExists.equalsIgnoreCase("1") ? 1 : 0);

                                spacecrafts.add(s);
                            }

                            //SET TO SPINNER
                            adapter =new ListViewAdapter(c,spacecrafts);
                            lv.setAdapter(adapter);

                        }catch (JSONException e)
                        {
                            Toast.makeText(c, "GOOD RESPONSE BUT JAVA CAN'T PARSE JSON IT RECEIEVED. "+e.getMessage(), Toast.LENGTH_LONG).show();

                        }

                    }

                    //ERROR
                    @Override
                    public void onError(ANError anError) {
                        anError.printStackTrace();
                        Toast.makeText(c, "UNSUCCESSFUL :  ERROR IS : "+anError.getMessage(), Toast.LENGTH_LONG).show();

                    }
                });
    }
}

(c). ListViewAdapter.java

We also have our ListView adapter to map our dataset to the adapterview.

package com.tutorials.hp.mysqllistviewbool.mAdapter;

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

import com.tutorials.hp.mysqllistviewbool.R;
import com.tutorials.hp.mysqllistviewbool.mModel.Spacecraft;

import java.util.ArrayList;

public class ListViewAdapter extends BaseAdapter {

    Context c;
    ArrayList<Spacecraft> spacecrafts;

    public ListViewAdapter(Context c, ArrayList<Spacecraft> spacecrafts) {
        this.c = c;
        this.spacecrafts = spacecrafts;
    }

    @Override
    public int getCount() {
        return spacecrafts.size();
    }

    @Override
    public Object getItem(int i) {
        return spacecrafts.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        if(view==null)
        {
            view= LayoutInflater.from(c).inflate(R.layout.model,viewGroup,false);
        }

        TextView txtName = (TextView) view.findViewById(R.id.nameTxt);
        TextView txtPropellant = (TextView) view.findViewById(R.id.txtPropellant);

        CheckBox chkTechExists = (CheckBox) view.findViewById(R.id.chkTechExists);

        final Spacecraft s= (Spacecraft) this.getItem(i);

        txtName.setText(s.getName());
        txtPropellant.setText(s.getPropellant());
        chkTechExists.setChecked( s.getTechnologyExists()==1);

        view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(c, s.getName(), Toast.LENGTH_SHORT).show();
            }
        });

        return view;
    }
}

(d). MainActivity.java

The main activity.

package com.tutorials.hp.mysqllistviewbool;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.TextInputEditText;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.Spinner;
import android.widget.Toast;

import com.tutorials.hp.mysqllistviewbool.mAdapter.ListViewAdapter;
import com.tutorials.hp.mysqllistviewbool.mModel.Spacecraft;
import com.tutorials.hp.mysqllistviewbool.mMySQL.MySQLClient;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    //INSTANCE FIELDS
    private TextInputEditText txtName;
    private CheckBox chkTechnologyExists;
    private Spinner spPropellant;
    private ListView lv;
    private Button btnAdd,btnRetrieve;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        //REFERENCE VIEWS
        this.initializeViews();

        populatePropellants();

        //HANDLE EVENTS
        this.handleClickEvents();

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                lv.setAdapter(new ListViewAdapter(MainActivity.this,new ArrayList<Spacecraft>()));
            }
        });

    }

    /*
    REFERENCE VIEWS
     */
    private void initializeViews()
    {

        txtName= (TextInputEditText) findViewById(R.id.nameTxt);
        chkTechnologyExists= (CheckBox) findViewById(R.id.techExists);
        spPropellant= (Spinner) findViewById(R.id.sp);
        lv= (ListView) findViewById(R.id.lv);

        btnAdd= (Button) findViewById(R.id.addBtn);
        btnRetrieve= (Button) findViewById(R.id.refreshBtn);

    }

    /*
    HANDLE CLICK EVENTS
     */
    private void handleClickEvents()
    {
        //EVENTS : ADD
        btnAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                //GET VALUES
                String name=txtName.getText().toString();
                String propellant=spPropellant.getSelectedItem().toString();
                Boolean technologyexists=chkTechnologyExists.isChecked();

                //BASIC CLIENT SIDE VALIDATION
                if((name.length()<1 || propellant.length()<1  ))
                {
                    Toast.makeText(MainActivity.this, "Please Enter all Fields", Toast.LENGTH_SHORT).show();
                }
                else
                {
                    //SAVE

                    Spacecraft s=new Spacecraft();
                    s.setName(name);
                    s.setPropellant(propellant);
                    s.setTechnologyExists(technologyexists ? 1 : 0);

                    new MySQLClient(MainActivity.this).add(s,txtName,spPropellant);
                }
            }
        });

        //EVENTS : RETRIEVE
        btnRetrieve.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                new MySQLClient(MainActivity.this).retrieve(lv);

            }
        });

    }

    private void populatePropellants()
    {
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_dropdown_item);

        adapter.add("None");
        adapter.add("Chemical Energy");
        adapter.add("Nuclear Energy");
        adapter.add("Laser Beam");
        adapter.add("Anti-Matter");
        adapter.add("Plasma Ions");
        adapter.add("Warp Drive");

        spPropellant.setAdapter(adapter);
        spPropellant.setSelection(0);

    }
}

Download

Hey,everything is in source code reference that is well commented and easy to understand and can be downloaded below.

Also check our video tutorial it’s more detailed and explained in step by step.