How to read data from database to applet

Question

hi i am writing a program below which reads data from mysql database successfully ;
import java.sql.*;
import java.lang.*;
import java.util.*;
public class Read_Capital_country_from_database {
public static void main (String args[] ){
int index,mess;
String country_arr[] = new String[250];
String capital_arr[] = new String[250];
int i = 0 ;
String URL = "jdbc:mysql://localhost/allusers";
String user = "shadab";
String password ="shadab@123";
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(URL,user,password);
for( SQLWarning warn = conn.getWarnings(); warn != null; warn = warn. getNextWarning() )
System.out.println( "SQL Warning:" ) ;
System.out.println( "State : " + warn.getSQLState() ) ;
System.out.println( "Message: " + warn.getMessage() ) ;
System.out.println( "Error : " + warn.getErrorCode() ) ;
String sql = "select * from country_capital";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);
while( rs.next() ) {
System.out.println( rs.getString(1) );
System.out.println(" " +rs.getString(2) );
System.out.println();
catch (SQLException se){
System.out.println( "SQL Exception:" ) ;
System.out.println("Exception - raju");
while( se != null )
System.out.println( "State : " + se.getSQLState() ) ;
System.out.println( "Message: " + se.getMessage() ) ;
System.out.println( "Error : " + se.getErrorCode() ) ;
se = se.getNextException() ;
catch( Exception e )
System.out.println( e ) ;
java Read_Capital_country_from_database
OUT PUT OF ABOVE PROGRAM IS :
INDIA NEW DELHI
PAKISTAN ISLAMABAD
AFGHANISTAN KABUL
BUT SAME PROGRAM WHEN I GO TO WRITE IN APPLET
THIS TIME APPLET DOES OPEN BUT ERROR SHOWS ON STANDARD OUT PUT
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
THIS IS THE PROGRAM WRITTEN FOR JAVA APPLET
import java.sql.*;
import java.lang.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class Read_Capital_country_from_database extends Applet {
Choice country, capital;
String msg=" ", msg1;
int index,mess;
String country_arr[] = new String[250];
String capital_arr[] = new String[250];
char chr;
int i = 0;
public void init() {
country = new Choice();
capital = new Choice();
String URL = "jdbc:mysql://localhost/allusers";
String user = "shadab";
String password ="shadab@123";
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(URL,user,password);
for( SQLWarning warn = conn.getWarnings(); warn != null; warn = warn. getNextWarning() )
System.out.println( "SQL Warning:" ) ;
System.out.println( "State : " + warn.getSQLState() ) ;
System.out.println( "Message: " + warn.getMessage() ) ;
System.out.println( "Error : " + warn.getErrorCode() ) ;
String sql = "select * from country_capital";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);
while( rs.next() ) {
country_arr[i] = rs.getString(1);
country.add(country_arr);
capital_arr[i] = rs.getString(2);
capital.add(capital_arr[i]);
i++;
catch (SQLException se){
System.out.println( "SQL Exception:" ) ;
System.out.println("Exception - raju");
while( se != null )
System.out.println( "State : " + se.getSQLState() ) ;
System.out.println( "Message: " + se.getMessage() ) ;
System.out.println( "Error : " + se.getErrorCode() ) ;
se = se.getNextException() ;
catch( Exception e )
System.out.println( e ) ;
add(country);
add(capital);

Answer 1

It doesn't make sense to read a database directly from an applet. If an applet needs data from a database is should request if from the server which the applet is located on and the server should do the actual database actions.
The whole point of applets is that they require no installation on the client machine. If you have to change policy files or the like, you might as well install a Swing application. Furthermore accessing a database tends to depend on how the client is set up on the network. Any sensible network has firewall settings that block access to the database ports to any external access (and, again, if you are limiting the facility to a few internal machines then why not just install a program on them).