Connecting to MySQL from Android with JDBC

Question

I used the following code to connect MySQL in localhost from Android. It only displays the actions given in catch section . I do not know whether it is a connection problem or not.

package com.test1;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class Test1Activity extends Activity {
    /** Called when the activity is first created. */
    String str="new";
    static ResultSet rs;
    static PreparedStatement st;
    static Connection con;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        final   TextView tv=(TextView)findViewById(R.id.user);

        try
        {
            Class.forName("com.mysql.jdbc.Driver");
              con=DriverManager.getConnection("jdbc:mysql://10.0.2.2:8080/example","root","");
            st=con.prepareStatement("select * from country where id=1");
            rs=st.executeQuery();
             while(rs.next())
             {
             str=rs.getString(2);


             }


            tv.setText(str);
            setContentView(tv);
        }
        catch(Exception e)
        {
            tv.setText(str);
        }
    }
}

When this code executes it displays "new" in the avd.

java.lang.management.ManagementFactory.getThreadMXBean, referenced from method com.mysql.jdbc.MysqlIO.appendDeadlockStatusInformation
Could not find class 'javax.naming.StringRefAddr', referenced from method com.mysql.jdbc.ConnectionPropertiesImpl$ConnectionProperty.storeTo
Could not find method javax.naming.Reference.get, referenced from method com.mysql.jdbc.ConnectionPropertiesImpl$ConnectionProperty.initializeFrom

Can anyone suggest some solution? And thanks in advance

Answer 1

You can't access a MySQL DB from Android natively. EDIT: Actually you may be able to use JDBC, but it is not recommended (or may not work?) ... see Android JDBC not working: ClassNotFoundException on driver

See

http://www.helloandroid.com/tutorials/connecting-mysql-database

http://www.basic4ppc.com/forum/basic4android-getting-started-tutorials/8339-connect-android-mysql-database-tutorial.html

Android cannot connect directly to the database server. Therefore we need to create a simple web service that will pass the requests to the database and will return the response.

http://codeoncloud.blogspot.com/2012/03/android-mysql-client.html

For most [good] users this might be fine. But imagine you get a hacker that gets a hold of your program. I've decompiled my own applications and its scary what I've seen. What if they get your username / password to your database and wreak havoc? Bad.

Answer 2

this code runs permanently!!! created by diko(Turkey)

public void mysql() {

    try {
        Class.forName("com.mysql.jdbc.Driver");
    } catch (ClassNotFoundException e) {
        e.printStackTrace();

    }

    thrd1 = new Thread(new Runnable() {
        public void run() {
            while (!Thread.interrupted()) {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e1) {

                }
                if (con == null) {
                    try {
                        con = DriverManager.getConnection("jdbc:mysql://192.168.1.45:3306/deneme", "ali", "12345");

                    } catch (SQLException e) {
                        e.printStackTrace();
                        con = null;
                    }

                    if ((thrd2 != null) && (!thrd2.isAlive()))
                        thrd2.start();

                }
            }

        }
    });
    if ((thrd1 != null) && (!thrd1.isAlive())) thrd1.start();

    thrd2 = new Thread(new Runnable() {
        public void run() {
            while (!Thread.interrupted()) {

                if (con != null) {
                    try {
                     //   con = DriverManager.getConnection("jdbc:mysql://192.168.1.45:3306/deneme", "ali", "12345");
                        Statement st = con.createStatement();
                        String ali = "'fff'";
                        st.execute("INSERT INTO deneme (name) VALUES(" + ali + ")");
                      //  ResultSet rs = st.executeQuery("select * from deneme");
                      //  ResultSetMetaData rsmd = rs.getMetaData();
                      //  String result = new String();


                      //  while (rs.next()) {
                      //      result += rsmd.getColumnName(1) + ": " + rs.getInt(1) + "\n";
                     //       result += rsmd.getColumnName(2) + ": " + rs.getString(2) + "\n";


                     //   }

                    } catch (SQLException e) {
                        e.printStackTrace();
                        con = null;
                    }

                    try {
                        Thread.sleep(10);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                } else {
                    try {
                        Thread.sleep(300);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }

    });


}

Answer 3

If u need to connect your application to a server you can do it through PHP/MySQL and JSON http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/ .Mysql Connection code should be in AsynTask class. Dont run it in Main Thread.

Answer 4

Do you want to keep your database on mobile? Use sqlite instead of mysql.

If the idea is to keep database on server and access from mobile. Use a webservice to fetch/ modify data.

Answer 5

An other approach is to use a Virtual JDBC Driver that uses a three-tier architecture: your JDBC code is sent through HTTP to a remote Servlet that filters the JDBC code (configuration & security) before passing it to the MySql JDBC Driver. The result is sent you back through HTTP. There are some free software that use this technique. Just Google "Android JDBC Driver over HTTP".

Answer 6

try changing in the gradle file the targetSdkVersion to 8

targetSdkVersion 8

Answer 7

public void testDB() {
        TextView tv = (TextView) this.findViewById(R.id.tv_data);
        try {

            Class.forName("com.mysql.jdbc.Driver");

            // perfect

            // localhost

            /*
             * Connection con = DriverManager .getConnection(
             * "jdbc:mysql://192.168.1.5:3306/databasename?user=root&password=123"
             * );
             */

            // online testing

            Connection con = DriverManager
                    .getConnection("jdbc:mysql://173.5.128.104:3306/vokyak_heyou?user=viowryk_hiweser&password=123");

            String result = "Database connection success\n";
            Statement st = con.createStatement();

            ResultSet rs = st.executeQuery("select * from tablename ");
            ResultSetMetaData rsmd = rs.getMetaData();

            while (rs.next()) {

                result += rsmd.getColumnName(1) + ": " + rs.getString(1) + "\n";

            }
            tv.setText(result);
        } catch (Exception e) {
            e.printStackTrace();
            tv.setText(e.toString());
        }

    }