Develop Reference

Connect android studio to azure sql database using Java

package com.example.workdb;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.os.AsyncTask;
import android.os.StrictMode;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.os.Bundle;
import android.widget.TextView;
import org.w3c.dom.Text;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import net.sourceforge.jtds.jdbc.*;
public class MainActivity extends AppCompatActivity {
public Button run;
public TextView message;
public TextView txtvw;
public Connection con;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
run= (Button) findViewById(R.id.button);
run.setOnClickListener(new View.OnClickListener() {
public void onClick(View v)
{
CheckLogin checkLogin= new CheckLogin();
checkLogin.execute("");
Log.d("CREATION","ON CREATE WORKS");
// Log.d("txtvw", connection);
//System.out.println("Yes");
// txtvw.setText("hello");
}
});
} public class CheckLogin extends AsyncTask<String,String,String>
{
String z="";
Boolean IsSuccess= false;
String name1="";
// Log.d("txtvw","step 1 done");
protected void onPostExecute(String r){
if (IsSuccess){
message=(TextView)findViewById(R.id.textView);
message.setText(name1);
Log.d("TAG", "STEP 1 DONE");
}
}
#Override
protected String doInBackground(String... strings) {
try
{
Connection con = connectionClass();
if(con==null){
z="Check interent";
//Log.d("txtvw", z);
}
else
{
String query= "select * from Value";
Statement stmt= con.createStatement();
ResultSet rs= stmt.executeQuery(query);
if (rs.next())
{
name1=rs.getString("KneeAngle");
Log.d("MYTAG", "name 1 works");
z="Query success";
IsSuccess=true;
con.close();
}
else{
z="Invalid query";
IsSuccess=false;
}
}
} catch (SQLException e) {
e.printStackTrace();
}
return z;
}
}
public Connection connectionClass(){
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
Connection connection = null;
String ConnectionURL ;
try{
Class.forName("net.sourceforge.jtds.jdbs.Driver");
ConnectionURL="jdbc:jtds:sqlserver://havvasemserv3.database.windows.net:1433;DatbaseName=Newfin;user=;password=;encrypt=true;trustServerCertificate=false;hostNameInCertificate=*.database.windows.net;loginTimeout=30";
connection= DriverManager.getConnection(ConnectionURL);
} catch(ClassNotFoundException e){
Log.e("Error here 2 ",e.getMessage());
}
catch (Exception e) {
Log.e("error here 3:",e.getMessage());
}
//Log.d("txtvw", connection);
return connection;
}
}
I am trying to connect azure sql database to android studio. I have added all the permissions in the manifest file and I have also added a jtds module 1.3.1 in the project and implemented it in the gradle module app. My code exits with 0 errors but data is not displayed on the emulator. Expected output is the first value from my database which is "8".
Thanks.,

Add this at the end of you current connection url after timeout=30
;ssl=request
Also make sure in your firewall settings of your azure server!/database your current device ip is allowed to access as by default all access is blocked,
To allow all devices to access server go to the firewall settings and in the insert ip section add this ip range
0,0,0,0 and 255,255,255,255

NullPointerException on grabbing sql data from database

I'm trying to pull all the data from a table using SELECT * from book, but I'm getting:
Attempt to invoke interface method 'java.sql.ResultSet java.sql.Statement.executeQuery(java.lang.String)' on a null object reference
I got it working when triggering the SQL statement in Eclipse. I'm trying to recreate it in Android Studio, but seems to throw this issue. Any help is appreciated.
SQL.java
package com.example.andy.loginapp;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
/**
* Created by Andy on 1/4/2017.
*/
public class SQL {
private Statement st;
private Connection con;
private ResultSet rs;
public SQL(){
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/sqltest", "root", "");
st = con.createStatement();
}
catch(Exception e){
System.out.println(e);
}
}
public void getData(){
try{
String query = "SELECT * from book";
String queryInsert = "INSERT into Book " + "VALUE(authorField.getText(), titleField.getText(), yearField.getText())";
rs = st.executeQuery(query);
while(rs.next()){
String author = rs.getString("author");
String title = rs.getString("title");
System.out.println("Author: " + author + " " + "Title" + " " + title);
}
}
catch(Exception e){
System.out.println(e);
}
System.out.println("success");
}
}
MainActivity.java
package com.example.andy.loginapp;
import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutCompat;
import android.view.View;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;
import org.w3c.dom.Text;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
public class MainActivity extends AppCompatActivity {
private Statement st;
private Connection con;
private ResultSet rs;
TextView hi;
RelativeLayout background;
Button sqlButton;
SQL data = new SQL();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sqlButton = (Button) findViewById(R.id.sqlButton);
sqlButton.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v) {
data.getData();
}
});
}
}

You would have to write a webservice to connect to any external databases such as MYSQL to connect android application to a database. It also involves writing a very basic PHP script.
See the following link for some examples.
https://www.b4x.com/android/forum/threads/connect-android-to-mysql-database-tutorial.8339/
http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/
So you're better off using SQLLite unless its absolutely necessary.

Bluemix: How to insert JSON in Cloudant in Android with Replicator?

I am finding it difficult to make this simple upload. I've used all encontrandos tutorials on the internet such as Bluelist and android-sync. I already have a database created within the service. My code is as follows:
MainActivity.java
package com.example.engenharia.replicator;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;
import com.cloudant.sync.datastore.BasicDocumentRevision;
import com.cloudant.sync.datastore.Datastore;
import com.cloudant.sync.datastore.DatastoreException;
import com.cloudant.sync.datastore.DatastoreManager;
import com.cloudant.sync.datastore.DocumentBodyFactory;
import com.cloudant.sync.datastore.DocumentException;
import com.cloudant.sync.datastore.DocumentRevision;
import com.cloudant.sync.datastore.MutableDocumentRevision;
import com.cloudant.sync.query.IndexManager;
import com.cloudant.sync.replication.ReplicatorBuilder;
import com.cloudant.sync.replication.Replicator;
import java.io.File;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
public class MainActivity extends AppCompatActivity {
private static final String DATASTORE_MANGER_DIR = "data";
private Datastore DataStore;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
URI uri = new URI(my_uri);
File path = getApplicationContext().getDir(DATASTORE_MANGER_DIR, Context.MODE_PRIVATE);
DatastoreManager manager = new DatastoreManager(path.getAbsolutePath());
DataStore = manager.openDatastore("banco0"); //banco0 is the DB created in Cloudant NoSQL service.
// Create a replicator that replicates changes from the local
// datastore to the remote database.
Replicator replicator = ReplicatorBuilder.push().to(uri).from(DataStore).build();
// Use a CountDownLatch to provide a lightweight way to wait for completion
CountDownLatch latch = new CountDownLatch(1);
Listener listener = new Listener(latch);
replicator.getEventBus().register(listener);
replicator.start();
latch.await();
replicator.getEventBus().unregister(listener);
if(replicator.getState() != Replicator.State.COMPLETE){
System.out.println("Error replicating TO remote");
System.out.println(listener.error);
} else {
System.out.println(String.format("Replicated %d documents in %d batches",
listener.documentsReplicated, listener.batchesReplicated));
}
}catch (Exception e){
e.printStackTrace();
}
}
public DocumentRevision createDocument() {
MutableDocumentRevision rev = new MutableDocumentRevision();
rev.body = DocumentBodyFactory.create(HashMap());
try {
return DataStore.createDocumentFromRevision(rev);
} catch (DocumentException e) {
//throw new RuntimeException(e);
e.printStackTrace();
return null;
}
}
public Map<String, Object> HashMap() {
HashMap<String, Object> map = new HashMap<String, Object>();
HashMap<String, String> map1 = new HashMap<String, String>();
map1.put("Street", "121");
map1.put("Street1", "12112");
map1.put("Street123", "1211111");
String[] array1 = new String[]{"Cloudant", "NoSQL", "JSON"};
map.put("address", map1);
map.put("description", "This is sample description");
map.put("skills", array1);
return map;
}
}
listener.java
package com.example.engenharia.replicator;
import com.cloudant.sync.notifications.ReplicationCompleted;
import com.cloudant.sync.notifications.ReplicationErrored;
import com.cloudant.sync.replication.ErrorInfo;
import com.google.common.eventbus.Subscribe;
import com.cloudant.sync.replication.ReplicatorBuilder;
import com.cloudant.sync.replication.Replicator;
import java.util.concurrent.CountDownLatch;
/**
* Created by engenharia on 19/08/16.
*/
public class Listener {
private final CountDownLatch latch;
public ErrorInfo error = null;
public int documentsReplicated;
public int batchesReplicated;
Listener(CountDownLatch latch) {
this.latch = latch;
}
#Subscribe
public void complete(ReplicationCompleted event) {
this.documentsReplicated = event.documentsReplicated;
this.batchesReplicated = event.batchesReplicated;
latch.countDown();
}
#Subscribe
public void error(ReplicationErrored event) {
this.error = event.errorInfo;
latch.countDown();
}
}
Executing this code I have the follow error:
CouchException: error: forbidden, reason: server_admin access is
required for this request, statusCode: 403, msg: null, cause: null
But I am the admin!
How do I fix the problem or what is the solution?

no communication between pub/sub code in android using zeromq

I tried to implement a simple publisher and subscriber in android using zeromq. When i try to debug it loops in subscriber recv. I dont know where i am going wrong. I think it is not able to get any data from the publisher.
Below is the code :subscriber
package com.example.jeromqps;
import java.util.*;
import org.jeromq.ZMQ;
import android.os.AsyncTask;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
public class client implements Runnable {
Messenger messenger;
public client()
{
System.out.println("client started");
}
#Override
public void run()
{
ZMQ.Context context=ZMQ.context(1);
System.out.println("collecting data from server");
ZMQ.Socket subscriber=context.socket(ZMQ.SUB);
subscriber.connect("tcp://localhost:4444");
String code="10001";
subscriber.subscribe(code.getBytes());
int totalvalue=0;
//store the data in a data structure
for(int i=0;i<10;i++)
{
byte[] msg = subscriber.recv(0);
String string=new String(subscriber.recv(0));
StringTokenizer sscanf=new StringTokenizer(string," ");
int value=Integer.valueOf(sscanf.nextToken());
String string= new String(msg);
System.out.println();
totalvalue+=value;
}
int avg=totalvalue;
Message msg1=Message.obtain();
msg1.obj=string;
try {
messenger.send(msg1);
System.out.println("sent to main");
} catch (RemoteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
subscriber.close();
context.term();
}
}
The publisher code is below
package com.example.jeromqps;
import java.util.*;
import org.jeromq.*;
public class server implements Runnable{
public server()
{
System.out.println("server started");
}
#Override
public void run()
{
ZMQ.Context context=ZMQ.context(1);
ZMQ.Socket publisher=context.socket(ZMQ.PUB);
publisher.bind("tcp://*:4444");
Random srandom=new Random(System.currentTimeMillis());
System.out.println("in server");
while(!Thread.currentThread().isInterrupted())
{ //System.out.println("in while")
int zipcode =1000 +srandom.nextInt(10000);
int temperature = srandom.nextInt(215) - 80 + 1;
String update = String.format("%05d %d", zipcode, temperature);
String update="publisher";
publisher.send(update.getBytes(),0);
}
publisher.close();
context.term();
}
}
Main is below:
package com.example.jeromqps;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.app.Activity;
import android.app.AlertDialog;
import android.os.Bundle;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.os.Handler;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MainActivity extends Activity implements Handler.Callback {
private TextView textView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new Thread(new server()).start();
new Thread(new client()).start();
}
#Override
public boolean handleMessage(Message arg0)
{
String str = new String((byte[]) arg0.obj);
System.out.println("****");
System.out.println(str);
//new AlertDialog.Builder(this).setMessage(str).show();
System.out.println("****");
textView.append(str+ "\n");
return false;
}
}
In program loops at byte[] msg = subscriber.recv(0); in the subscribers class. Where am i going wrong?Am i missing something?

First of all, you've got some errors in the code:
In the publisher, update is defined twice
String update = String.format("%05d %d", zipcode, temperature);
String update= "publisher";
You have a similar problem in the subscriber code, string is defined twice...
String string = new String(subscriber.recv(0));
String string = new String(msg);
In the subscriber, you're receiving messages twice in the same iteration..
byte[] msg = subscriber.recv(0);
String string = new String(subscriber.recv(0));
...you only need this in the loop to receive...
String string = new String(subscriber.recv(0));
Try fixing those problems and see how far you get...

This isn't a solution to the question posted here, but reading this question I noticed that 0 was specified as the second parameter in the send(...) method, which subsequently matches the parameter set in the recv(...) method.
I have a simple pub/sub system set up and couldn't figure out why messages weren't being sent. I was using recv(0) but was specifying some random flag in the send(...) method. Changing the value to 0 fixed my issues.
Figured I'd post this here as it was from reading through the code in the question that I happened to have that thought. So maybe this will help someone else in the future.

toast mesage not shown on screen when network or server not available

I need to show toast message when the server is not responding
when I press the login button, some parameters are passed to AgAppMenu screen which use url connection to server and get xml response in AgAppHelperMethods screen. The
probelm is when the server is busy or the network is not avaibale, I can't show toast message on catch block although it shows the log message.
import android.app.Activity;
import android.app.AlertDialog;
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.TextView;
import android.widget.Toast;
public class LoginScreen extends Activity implements OnClickListener {
EditText mobile;
EditText pin;
Button btnLogin;
Button btnClear;
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.agapplogin);
TextView lblMobileNo = (TextView) findViewById(R.id.lblMobileNo);
lblMobileNo.setTextColor(getResources()
.getColor(R.color.text_color_red));
mobile = (EditText) findViewById(R.id.txtMobileNo);
TextView lblPinNo = (TextView) findViewById(R.id.lblPinNo);
lblPinNo.setTextColor(getResources().getColor(R.color.text_color_red));
pin = (EditText) findViewById(R.id.txtPinNo);
btnLogin = (Button) findViewById(R.id.btnLogin);
btnClear = (Button) findViewById(R.id.btnClear);
btnLogin.setOnClickListener(new OnClickListener() {
public void onClick(View view) {
postLoginData();
}
});
btnClear.setOnClickListener(new OnClickListener() {
public void onClick(View v)
{
cleartext();
}
});
/*
*
* btnClear.setOnClickListener(new OnClickListener() { public void
* onClick(View arg0) {
*
* } });
*/
}
public void postLoginData()
{
if (pin.getTextSize() == 0 || mobile.getTextSize() == 0) {
AlertDialog.Builder altDialog = new AlertDialog.Builder(this);
altDialog.setMessage("Please Enter Complete Information!");
} else {
Intent i = new Intent(this.getApplicationContext(), AgAppMenu.class);
Bundle bundle = new Bundle();
bundle.putString("mno", mobile.getText().toString());
bundle.putString("pinno", pin.getText().toString());
i.putExtras(bundle);
startActivity(i);
}
}
#Override
public void onClick(View v) {
}
public void cleartext() {
{
pin.setText("");
mobile.setText("");
}
}
}
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class AgAppMenu extends Activity {
String mno, pinno;
private String[][] xmlRespone;
Button btnMiniStatement;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.agappmenu);
mno = getIntent().getExtras().getString("mno");
pinno = getIntent().getExtras().getString("pinno");
setTitle("Welcome to the Ag App Menu");
AgAppHelperMethods agapp =new AgAppHelperMethods();
// xmlRespone = AgAppHelperMethods.AgAppXMLParser("AG_IT_App/AgMainServlet?messageType=LOG&pin=" + pinno + "&mobile=" + mno + "&source=" + mno + "&channel=INTERNET");
xmlRespone = agapp.AgAppXMLParser("AG_IT_App/AgMainServlet?messageType=LOG&pin=" + pinno + "&mobile=" + mno + "&source=" + mno + "&channel=INTERNET");
import java.net.URL;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;
import android.view.View;
import android.view.View.OnKeyListener;
public class AgAppHelperMethods extends Activity {
private static final String LOG_TAG = null;
private static AgAppHelperMethods instance = null;
public static String varMobileNo;
public static String varPinNo;
String[][] xmlRespone = null;
boolean flag = true;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.agapphelpermethods);
}
protected AgAppHelperMethods() {
}
public static AgAppHelperMethods getInstance() {
if (instance == null) {
instance = new AgAppHelperMethods();
}
return instance;
}
public static String getUrl() {
String url = "https://demo.accessgroup.mobi/";
return url;
}
public String[][] AgAppXMLParser(String parUrl) {
String _node, _element;
String[][] xmlRespone = null;
try {
String url = AgAppHelperMethods.getUrl() + parUrl;
URL finalUrl = new URL(url);
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(new InputSource(finalUrl.openStream()));
doc.getDocumentElement().normalize();
NodeList list = doc.getElementsByTagName("*");
_node = new String();
_element = new String();
xmlRespone = new String[list.getLength()][2];
// this "for" loop is used to parse through the
// XML document and extract all elements and their
// value, so they can be displayed on the device
for (int i = 0; i < list.getLength(); i++) {
Node value = list.item(i).getChildNodes().item(0);
_node = list.item(i).getNodeName();
_element = value.getNodeValue();
xmlRespone[i][0] = _node;
xmlRespone[i][1] = _element;
}// end for
throw new ArrayIndexOutOfBoundsException();
}// end try
// will catch any exception thrown by the XML parser
catch (Exception e) {
Toast.makeText(AgAppHelperMethods.this,
"error server not responding " + e.getMessage(),
Toast.LENGTH_SHORT).show();
Log.e(LOG_TAG, "CONNECTION ERROR FUNDAMO SERVER NOT RESPONDING", e);
}
// Log.e(LOG_TAG, "CONNECTION ERROR FUNDAMO SERVER NOT RESPONDING", e);
return xmlRespone;
}
`

AgAppHelperMethods isn't really an Activity. You've derived this class from Activity, but then you've created Singleton management methods (getInstance()) and you are instantiating it yourself. This is bad. Don't do this.
Normally Android controls the instantiation of activities. You don't ever create one yourself (with new).
It looks to me like AgAppHelperMethods just needs to be a regular Java class. It doesn't need to inherit from anything. Remove also the lifecycle methods like onCreate().
Now you will have a problem with the toast, because you need a context for that and AgAppHelperMethods isn't a Context. To solve that you can add Context as a parameter to AgAppXMLParser() like this:
public String[][] AgAppXMLParser(Context context, String parUrl) {
...
// Now you can use "context" to create your toast.
}
When you call AgAppXMLParser() from AgAppMenu just pass "this" as the context parameter.