Develop Reference

Accessing database on server using android studio

I'm a complete beginner in android programming and am trying to make an app which requires access to the database on local host using the android studio, using the IP address of the server, I've watched many tutorial videos but still am not sure where to pass the IP address of the server.
The server uses MySQL, I've tried using JDBC but still unable to achieve the result.
Here is my code, any help would be appreciated.
`package com.example.vishal.connectiontest;
import java.sql.*;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import static android.R.attr.name;
import static com.example.vishal.connectiontest.DemoClass.main;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button B1 = (Button)findViewById(R.id.button);
final TextView e1 = (TextView) findViewById(R.id.HelloWorld);
B1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try{
String result = main();
e1.setText(result.toString());
}
catch(java.lang.Exception e){
System.out.println("Exception");
}
}
});
}
}
class DemoClass
{
public static String main()throws Exception
{
String url = "jdbc:mysql://125.10.10.214/demo" ;
String uname = "root";
String pass = "";
String ip = "";
String query = "Select UserName from user_info where Id = '90000515'";
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection(url, uname,pass);
Statement st = con.createStatement();
ResultSet rs = st.executeQuery(query);
rs.next();
String name = rs.getString("UserName");
return (name);
}
}`

Easiest way of integrating Database to your Android Application is using Firebase.
It's really easy to use and other than Database, it has File Storage Services, Cloud Messaging, Analytics and many more.
I would recommend use of firebase database.
Here have a look at it's Documentation:
https://firebase.google.com/docs/database/

Reading file from AVD sd card and displaying text view

I have a text file that has this information
Casino Canberra;21 Binara Street, Canberra ACT, 2601;Canberra Casino is a casino located in Civic in the central part of the Australian capital city of Canberra. The Casino is relatively small compared with other casinos in Australia.;(02) 6257 7074;www.canberracasino.com.au
National Museum of Canberra;Parkes Place, Canberra ACT, 2601;The National Museum of Australia explores the land, nation and people of Australia. Open 9am - 5pm every day except Christmas Day. General admission free.;(02) 6240 6411;www.nga.gov.au
which is stored in the sdcard
after this i retrieve the values using this method
package au.edu.canberra.g30813706;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Environment;
public class FileReader extends Activity{{
ArrayList<read> sInfo = new ArrayList<read>();
ArrayList<String> sLines = new ArrayList<String>();
String line;
String[] saLineElements;
String txtName = "AccomodationTxt.txt";
File root = Environment.getExternalStorageDirectory();
File path = new File(root, "CanberraTourism/" + txtName);
try {
BufferedReader br = new BufferedReader (
new InputStreamReader(
new FileInputStream(path)));
while ((line = br.readLine()) != null)
{
sLines.add(line);
//The information is split into segments and stored into the array
saLineElements = line.split(";");
//for (int i = 0; i < saLineElements.length; i++)
// sInfo.add(new read(saLineElements[i]));
sInfo.add(new read(saLineElements[0], saLineElements[1], saLineElements[3], saLineElements[4], saLineElements[5]));
}
br.close();
}
catch (FileNotFoundException e) {
System.err.println("FileNotFoundException: " + e.getMessage());
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}}
}
But i also have and object class to store each individual item into
package au.edu.canberra.g30813706;
public class read {
public String name;
public String address;
public String info;
public String phone;
public String www;
public read (String name, String address, String info, String phone, String www)
{
this.name = name;
this.address = address;
this.info = info;
this.phone = phone;
this.www = www;
}
}
The only issue im having is trying to display the information in a text view which i have no idea how to call the values i need
This is where im trying to insert it
package au.edu.canberra.g30813706;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import au.edu.canberra.g30813706.FileReader;
import au.edu.canberra.g30813706.read;
public class Accommodation_info extends Activity{
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.accommodation_layout);
}}

You should probably look into using the Application class. You can think of Application as a GUI-less activity which works like the model in a program following the MVC pattern. You can put all of your read objects into a data structure in your Application and then access them with accessors and mutators of your own design.
Take a look at this official doc.
As your code stands, you can only access your instances of read by obtaining a reference to your FileReader class, but your two activities are separate entities. You'd have to do something like this:
// This is the main activity and should be launched first
// Check your manifest to make sure it launches with this activity
package au.edu.canberra.g30813706;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
import au.edu.canberra.g30813706.FileReader;
import au.edu.canberra.g30813706.read;
public class Accommodation_info extends Activity
{
// Declare the file reader so you'll have a reference
FileReader reader;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.accommodation_layout);
// Instantiate the file reader
reader = new FileReader();
// Now you can access the array inside FileReader
// obviously, you need to have a text view called my_textView defined in the
// layout file associated with this activity
TextView myTextView = (TextView)findViewById(R.id.my_textView);
// displays the first element in FileReader's array list
myTextView.setText((String)reader.get(0));
}}
At the moment, you might be in a bit deep for your current understanding of Android and/or Java. I would encourage you to follow as many code examples as possible, get comfortable with Android and then go back to your project when you have a little more experience.

How to make a connection with my ontology?

I created an ontology with Protégé. Then I created an Android interface which contains two edit texts and a button. The main function of my code is to make a connection between my application and the ontology and store these data into it. I use a triple store for storage.
But it didn't work correctly. I'm using Sesame as server but I don't know how to get the correct URL of the "update" service. I might have made other errors but here is my activity's code:
package com.example.ontologie1;
import com.hp.hpl.jena.ontology.DatatypeProperty;
import com.hp.hpl.jena.ontology.Individual;
import com.hp.hpl.jena.ontology.OntClass;
import com.hp.hpl.jena.ontology.OntModel;
import com.hp.hpl.jena.ontology.OntModelSpec;
import com.hp.hpl.jena.rdf.model.Literal;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.rdf.model.Property;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import java.io.IOException;
import org.apache.commons.httpclient.NameValuePair;
import org.apache.commons.httpclient.methods.PostMethod;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity {
private Button buttonconnexion;
private EditText editpseudo;
private EditText editpassword;
public String ps;
public String pa;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editpseudo = (EditText) findViewById(R.id.welcomeedittextlogin);
editpassword = (EditText) findViewById(R.id.welcomeedittextpassword);
buttonconnexion = (Button) findViewById(R.id.welcomebuttonconnexion);
buttonconnexion.setOnClickListener(click1);
}
protected OnClickListener click1 = new OnClickListener() {
public void onClick(View arg0) {
ps= editpseudo.getText().toString();
pa= editpassword.getText().toString();
try {
connexion(ps , pa);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
protected void connexion(String pseudo,String password) throws IOException {
String requete = "<http://www.w3.org/2002/07/owl#> .\n"
+ "INSERT DATA {\n"
+ " <http://www.owl-ontologies.com/Ontology_profile.owl#USER> a onto:USER;\n"
+ " onto:Login " + pseudo + ";\n"
+ " onto:Password " + password + ";\n"
+ "}";
PostMethod post = new PostMethod("<http://www.openrdf.org/config/repository#>");
NameValuePair[] paramRequete = {
new NameValuePair("query", requete),
};
post.setRequestBody(paramRequete);
InputStream in = post.getResponseBodyAsStream();
Toast t = null ;
t.setText(in.toString());
t=new Toast(null);
}
}

I don't have experience with Android programming, but there are some issues that suggest you need to rethink your goals.
An ontology is not a database. You don't store data in an ontology, and you don't need an ontology to store data in a triplestore.
To store data in a triplestore (using SPARQL), your triplestore needs a SPARQL endpoint. That endpoint has a URI that you send your POST or GET request to. If you installed Sesame on your local machine, that URI may look like http://localhost:8080/sparql. If you want to insert data, the triplestore needs to allow that.
You also need a valid SPARQL query, which your requete is not. The first line,
<http://www.w3.org/2002/07/owl#> .
is not complete. Usually there are PREFIXes on the first lines of a SPARQL query, but they don't end with a .. For example:
PREFIX owl: <http://www.w3.org/2002/07/owl#>
To use the prefix onto: as you do, you need to define it in the same way. For a complete SPARQL tutorial, see this.
Also, the lines
Toast t = null ;
t.setText(in.toString());
t=new Toast(null);
will generate a NullPointerException, as you call a method on t that is null.

Parsing a text file using Jsoup

I have a Continent.txt file placed in my res/raw folder. Inside it contains the following.
<div class="continents">
US
Canada
Europe
</div>
I am able to parse the text US, Canada, Europe using jsoup, but when I display them to a TextView, they show up in one line. The output looks like this.
US Canada Europe
I want the ouput to be like this.
US
Canada
Europe
This is my code.
package com.example.readfile;
import java.io.InputStream;
import java.util.ArrayList;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.content.res.Resources;
import android.widget.TextView;
public class MainActivity extends Activity {
TextView txtContinent;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txtContinent = (TextView) findViewById(R.id.textView1);
new MyTask().execute();
}
class MyTask extends AsyncTask<Void, Void, ArrayList<String>> {
ArrayList<String> arr_linkText = new ArrayList<String>();
#Override
protected ArrayList<String> doInBackground(Void... params) {
Document doc;
try {
Resources res = getResources();
InputStream in_s = res.openRawResource(R.raw.continent);
byte[] b = new byte[in_s.available()];
in_s.read(b);
doc = Jsoup.parse(new String(b));
Element link = doc.select("a").first();
String text = doc.body().text();
arr_linkText.add(text);
} catch (Exception e) {
// e.printStackTrace();
txtContinent.setText("Error: can't open file.");
}
return arr_linkText; // << retrun ArrayList from here
}
#Override
protected void onPostExecute(ArrayList<String> result) {
for (String temp_result : result) {
txtContinent.append(temp_result + "\n");
}
}
}
}
I do not know how to read the file line by line, I hope someone can illustrate it to me. Thank you!

You are taking the text of the entire body of the document at once. You need to parse it out by each element, like so
Elements links = doc.select("a");
for (Element link : links) {
arr_linkText.add(link.text());
}
in case it wasn't clear, the above code is meant to replace the following --
Element link = doc.select("a").first();
String text = doc.body().text();
arr_linkText.add(text);

Have you set android:inputType to include textMultiLine?

How to read data from a Google spreadsheet for an Android app

I have a public google spreadsheet with some data in tables.
I'm developing an Android app which I want it to read these tables and then make a listview with the fields on the spreadsheet.
Which will be the best way to do that?

You can use the code of James Moore: http://blog.restphone.com/2011/05/very-simple-google-spreadsheet-code.html.
package com.banshee;
import java.io.IOException;
import java.net.URL;
import com.google.gdata.client.spreadsheet.SpreadsheetService;
import com.google.gdata.data.spreadsheet.CustomElementCollection;
import com.google.gdata.data.spreadsheet.ListEntry;
import com.google.gdata.data.spreadsheet.ListFeed;
import com.google.gdata.util.ServiceException;
public class SpreadsheetSucker {
public static void main(String[] args) {
SpreadsheetService service = new SpreadsheetService("com.banshee");
try {
// Notice that the url ends
// with default/public/values.
// That wasn't obvious (at least to me)
// from the documentation.
String urlString = "https://spreadsheets.google.com/feeds/list/0AsaDhyyXNaFSdDJ2VUxtVGVWN1Yza1loU1RPVVU3OFE/default/public/values";
// turn the string into a URL
URL url = new URL(urlString);
// You could substitute a cell feed here in place of
// the list feed
ListFeed feed = service.getFeed(url, ListFeed.class);
for (ListEntry entry : feed.getEntries()) {
CustomElementCollection elements = entry.getCustomElements();
String name = elements.getValue("name");
System.out.println(name);
String number = elements.getValue("Number");
System.out.println(number);
}
} catch (IOException e) {
e.printStackTrace();
} catch (ServiceException e) {
e.printStackTrace();
}
}
}

I have developed a client Lib for SpreadSheet which works on Android. Please try-
http://code.google.com/p/google-spreadsheet-lib-android/
hope it helps.
Cheers,
Prasanta