Connect to mysql database in Android with java [duplicate]

I have installed mysql in my computer.and also have jetty.. My requirement:- I have a database student with table name ari; ari table is:-

+----+-------+
| id | name  |
+----+-------+
| 22 | Sandy |
+----+-------+

from My Android program I want to fetch it from database..I have done this:- MainActivity.java

public class MainActivity extends Activity {
    private static final String url = "jdbc:mysql://localhost:3306/student";
    private static final String user = "root";
    private static final String pass = "root";
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        testDB();
    }
public void testDB() {
        TextView tv = (TextView)this.findViewById(R.id.textView1);
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(url, user, pass);
            String result = "Database connection success\n";
            Statement st = con.createStatement();
            ResultSet rs = st.executeQuery("select * from ari");
            ResultSetMetaData rsmd = rs.getMetaData();
while(rs.next()) {
                result += rsmd.getColumnName(1) + ": " + rs.getInt(1) + "\n";
                result += rsmd.getColumnName(2) + ": " + rs.getString(2) + "\n";
                        }
            tv.setText(result);
        }
        catch(Exception e) {
            e.printStackTrace();
            tv.setText(e.toString());
        }   
    }
}

and activity_main.xml is:--

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    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" >
    <TextView
         android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
</RelativeLayout>

and the manifext file is:---

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.TourBus.info"
    android:versionCode="1"
    android:versionName="1.0-SNAPSHOT" >
    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.INTERNET" /> 
    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

But the problem is when I run that program in my android phone or emulator it is showing that:--

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException:  
Could not create connection to database server. 

I also have the jar file:--

mysql-connector-java

can anybody help me??pls