hi all,

i got this example from a website, but unfortunately i cant understand some cording in that source.

the green color lines are the difficult points that i could not understand.

also the database name, user name and password has not specified at anywhere in this cord.

how can i make this cord to run without problems....?

please help me.

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.ConnectionPoolDataSource;
import javax.sql.PooledConnection;

public class MainClass {
public static void main(String[] args) {
Connection connection = null;
Statement statement = null;
ResultSet resultSet = null;

try {
connection = getConnection();
// Do work with connection
statement = connection.createStatement();
String selectEmployeesSQL = "SELECT * FROM employees";
resultSet = statement.executeQuery(selectEmployeesSQL);

while (resultSet.next()) {
} catch (Exception e) {
} finally {
if (resultSet != null) {
try {
} catch (SQLException e) {
}// nothing we can do
if (statement != null) {
try {
} catch (SQLException e) {
} // nothing we can do
if (connection != null) {
try {
} catch (SQLException e) {
} // nothing we can do

private static Connection getConnection() throws NamingException, SQLException {
InitialContext initCtx = createContext();
String jndiName = "HrDS";
ConnectionPoolDataSource dataSource = (ConnectionPoolDataSource) initCtx.lookup(jndiName);
PooledConnection pooledConnection = dataSource.getPooledConnection();
return pooledConnection.getConnection(); // Obtain connection from pool

private static InitialContext createContext() throws NamingException {
Properties env = new Properties();
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.rmi.registry.RegistryContextFactory");
env.put(Context.PROVIDER_URL, "rmi://localhost:1099");
InitialContext context = new InitialContext(env);
return context;

private static void printEmployee(ResultSet resultSet) throws SQLException {
System.out.print(resultSet.getInt("employee_id")+", ");
System.out.print(resultSet.getString("last_name")+", ");
System.out.print(resultSet.getString("first_name")+", ");


If that's part of a JSP, never look at that example again.
That sort of code (or indeed ANY code) does NOT belong in a JSP.
Nor should anyone, ever, directly reference any of the classes in the com.sun packages.
This code references a connection pool provided by an application server.
The application server itself will hold the actual database configuration, including database URL, username, password, driverclass, etc. etc..

This article has been dead for over six months. Start a new discussion instead.