Welcome back!! We are well on our way to building our first android app - a complete E-Commerce Application.
I assume you would have gone through Step 1 and Step 2 becoming coming here. If you haven't, please go through them as well.
In this step, we are trying to create the Splash screen for our Application, create database and tables and also fetch data from Server in JSON format through AsyncTask.
Please watch our video to get a detailed understanding of how the code works.
I assume you would have gone through Step 1 and Step 2 becoming coming here. If you haven't, please go through them as well.
In this step, we are trying to create the Splash screen for our Application, create database and tables and also fetch data from Server in JSON format through AsyncTask.
Please watch our video to get a detailed understanding of how the code works.
The source code is attached.
The RESTful API which is being called is http://lawgo.in/lawgo/city?format=json
JSONParser.java
package com.zing.basket;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.json.JSONException;
import org.json.JSONObject;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) throws Exception {
// Making HTTP request
try {
HttpParams httpParameters = new BasicHttpParams();
int timeoutConnection = 20000;
HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
// Set the default socket timeout (SO_TIMEOUT)
// in milliseconds which is the timeout for waiting for data.
int timeoutSocket = 25000;
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
httpClient.setParams(httpParameters);
//HttpPost httpPost = new HttpPost(url);
HttpGet httpPost = new HttpGet(url);
HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
/*HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();*/
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
//Log.d("string","string is "+json);
} catch (Exception e) {
//Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
//Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
activity_start_screen.xml
<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:background="#B22222"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".StartScreen">
<TextView
android:id="@+id/SelectCityText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="107dp"
android:gravity="center"
android:text="@string/app_name"
android:textColor="#F8F8FF"
android:textSize="40sp"/>
<RelativeLayout>
StartScreen.java
package com.zing.basket;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ActionBar;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.Menu;
import android.widget.Toast;
public class StartScreen extends Activity {
SQLiteDatabase sqLite;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start_screen);
//initializing the action bar and hiding it.
ActionBar actionBar = getActionBar();
actionBar.hide();
//create a database if it doesnt exist, if it exists, it will open the database.
sqLite=this.openOrCreateDatabase("basketbuddy", MODE_PRIVATE, null);
sqLite.execSQL("CREATE TABLE IF NOT EXISTS USER (USER_ID VARCHAR,NAME VARCHAR,EMAIL VARCHAR)");
sqLite.execSQL("CREATE TABLE IF NOT EXISTS CITY_LIST (ID INTEGER primary key autoincrement,CITY_NAME VARCHAR)" );
sqLite.execSQL("CREATE TABLE IF NOT EXISTS USER_PREF (ID INTEGER primary key autoincrement,CITY_NAME VARCHAR default 'NONE', VOICE_ON VARCHAR, NOTIF VARCHAR)" );
sqLite.execSQL("CREATE TABLE IF NOT EXISTS CHECKLIST (ID INTEGER primary key autoincrement, PRODUCT_NAME VARCHAR, PRODUCT_CHECKED VARCHAR)");
sqLite.execSQL("CREATE TABLE IF NOT EXISTS PRODUCT_MASTER (ID INTEGER primary key autoincrement, PRODUCT_CODE INTEGER, PRODUCT_DIVISION INTEGER, PRODUCT_DEPARTMENT INTEGER"+
"PRODUCT_GF INTEGER, PRODUCT_F INTEGER, PRODUCT_SUBF INTEGER, PRODUCT_NAME VARCHAR, PRODUCT_BARCODE INTEGER, PRODUCT_GRAMMAGE VARCHAR, PRODUCT_MRP INTEGER, PRODUCT_BBPRICE INTEGER)");
sqLite.execSQL("CREATE TABLE IF NOT EXISTS CART (ID INTEGER primary key autoincrement, PRODUCT_CODE INTEGER, PRODUCT_DIVISION INTEGER, PRODUCT_DEPARTMENT INTEGER"+
"PRODUCT_GF INTEGER, PRODUCT_F INTEGER, PRODUCT_SUBF INTEGER, PRODUCT_NAME VARCHAR, PRODUCT_BARCODE VARCHAR, PRODUCT_GRAMMAGE VARCHAR, PRODUCT_MRP INTEGER, PRODUCT_BBPRICE INTEGER, PRODUCT_QTY INTEGER, PRODUCT_VALUE INTEGER)");
//call asynctask to fetch list of city to populate the dropdown.
updateList ul=new updateList();
ul.execute();
}
class updateList extends AsyncTask<Void, Void, String>
{
JSONParser jParser;
String url=new String();
@Override
protected void onPreExecute() {
super.onPreExecute();
url="http://lawgo.in/lawgo/city?format=json";
jParser = new JSONParser();
}
@Override
protected String doInBackground(Void... params)
{
try
{
JSONObject json=jParser.getJSONFromUrl(url);
Cursor sample;
try
{
JSONArray jar=json.getJSONArray("city");
Log.d("arindam", ""+jar.length());
for(int i=0;i<jar.length();i++)
{
JSONObject j=jar.getJSONObject(i);
//check if the city is already there in citylist.
sample=sqLite.rawQuery("SELECT CITY_NAME FROM CITY_LIST WHERE CITY_NAME='"+j.getString("cityname")+"'",null);
if(sample.moveToFirst())
{
continue;
}
else
{
sqLite.execSQL("insert into CITY_LIST (CITY_NAME) VALUES ('"+j.getString("cityname")+"')");
Log.d("arindam",j.getString("cityname"));
}
}
} catch (JSONException e)
{
// TODO Auto-generated catch block
return "perror";
}
}
catch(Exception e)
{
e.printStackTrace();
return "error";
}
return "success";
}
protected void onPostExecute(String result)
{
super.onPostExecute(result);
if(result.equals("perror"))
{
moveTaskToBack(true);
Toast.makeText(getApplicationContext(), "Error!!! Oops..that was humiliating. Could you please try again", Toast.LENGTH_LONG).show();
}
else if(result.equals("error"))
{
moveTaskToBack(true);
Toast.makeText(getApplicationContext(), "Please Check your Internet Connection", Toast.LENGTH_LONG).show();
}
else
{
new Handler().postDelayed(new Runnable(){
@Override
public void run()
{
Cursor c=sqLite.rawQuery("SELECT CITY_NAME FROM USER_PREF",null);
Log.d("arindam" ,"c count"+c.getCount());
if (c.getCount()== 0)
{
sqLite.execSQL("INSERT INTO USER_PREF (CITY_NAME, VOICE_ON, NOTIF) VALUES('NONE','Y','Y')");
}
Cursor d=sqLite.rawQuery("SELECT CITY_NAME FROM USER_PREF",null);
Log.d("arindam" ,"d count"+d.getCount());
if(d.moveToFirst())
{
Log.d("arindam" ,"d NONE"+d.getString(0));
if(d.getString(0).equals("NONE"))
{
//Intent intent=new Intent(StartScreen.this,CityScreen.class);
//startActivity(intent);
}
else
{
//Intent intent=new Intent(StartScreen.this,HomeScreen.class);
//startActivity(intent);
}
finish();
}
}
},1000);
}
}
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
}
@Override
public void onDestroy()
{
super.onDestroy();
sqLite.close();
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.zing.basket"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.zing.basket.StartScreen"
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>
if we want to fetch data from database how we can do that ? instead of server ..
ReplyDeletelike if i want to change city name how can i do that
That is very simple. Write a SQLite query to read all the rows from your city name table. Once read, populate the city names into the same ArrayList that we are populating the data from JSON. Rest all remains the same.
Delete