Java Development Tools

Hi experts,

This is first webpage i try to build using JDeveloper 10g. I followed step by step of "Oracle database 2 Day + Java Developer’s Guide". But when run this page, system warn:

500 Internal Server Error
java.sql.SQLException: Fail to convert to internal representation at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:138) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:175) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:240) at oracle.sql.CHAR.doubleValue(CHAR.java:496) at oracle.jdbc.driver.ScrollableResultSet.getDouble(ScrollableResultSet.java:593) at oracle.jdbc.driver.OracleResultSet.getDouble(OracleResultSet.java:1654) at product.jspService(_product.java:63) [product.jsp] at com.orionserver[Oracle Containers for J2EE 10g (10.1.3.4.0) ].http.OrionHttpJspPage.service(OrionHttpJspPage.java:59) at oracle.jsp.runtimev2.JspPageTable.service(JspPageTable.java:462) at oracle.jsp.runtimev2.JspServlet.internalService(JspServlet.java:594) at oracle.jsp.runtimev2.JspServlet.service(JspServlet.java:518) at javax.servlet.http.HttpServlet.service(HttpServlet.java:856) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.4.0) ].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:713) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.4.0) ].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:370) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.4.0) ].server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler.java:871) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.4.0) ].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:453) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.4.0) ].server.http.HttpRequestHandler.serveOneRequest(HttpRequestHandler.java:221) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.4.0) ].server.http.HttpRequestHandler.run(HttpRequestHandler.java:122) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.4.0) ].server.http.HttpRequestHandler.run(HttpRequestHandler.java:111) at oracle.oc4j.network.ServerSocketReadHandler$SafeRunnable.run(ServerSocketReadHandler.java:260) at oracle.oc4j.network.ServerSocketAcceptHandler.procClientSocket(ServerSocketAcceptHandler.java:234) at oracle.oc4j.network.ServerSocketAcceptHandler.access$700(ServerSocketAcceptHandler.java:29) at oracle.oc4j.network.ServerSocketAcceptHandler$AcceptHandlerHorse.run(ServerSocketAcceptHandler.java:879) at com.evermind[Oracle Containers for J2EE 10g (10.1.3.4.0) ].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:298) at java.lang.Thread.run(Thread.java:595)



This is my code:

package hr;
import java.sql.Connection;
import java.sql.SQLException;
import oracle.jdbc.pool.OracleDataSource;
import java.sql.Statement;
import java.sql.ResultSet;

import javax.servlet.http.HttpSession;


public class DataHandler {
public DataHandler() {
}
String jdbcUrl = "jdbc:oracle:thin:@localhost:1521:ORCL";
String userid = "srdemo";
String password = "oracle";
Connection conn;
Statement stmt;
ResultSet rset;
String query;
String sqlString;


public void getDBConnection() throws SQLException{
OracleDataSource ds;


ds = new OracleDataSource();
ds.setURL(jdbcUrl);
conn=ds.getConnection(userid,password);
}
public ResultSet getAllEmployees() throws SQLException{
getDBConnection();
stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
query = "SELECT * FROM products";
System.out.println("\nExecuting query: " + query);
rset = stmt.executeQuery(query);
return rset;

}

public ResultSet getEmployeesByName(String name) throws SQLException {
name = name.toUpperCase();
getDBConnection();
stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_READ_ONLY);
query =
"SELECT * FROM products WHERE UPPER(name) LIKE '%" + name + "%' order by prod_id";
System.out.println("\nExecuting query: " + query);
rset = stmt.executeQuery(query);
return rset;
}
public static void main(String[] args) throws Exception{
DataHandler datahandler = new DataHandler();
ResultSet rset = datahandler.getAllEmployees();
while (rset.next()) {
System.out.println(rset.getInt(1) + " " +
rset.getString(2) + " " +
rset.getString(3) + " " +
rset.getString(4));
}
rset = datahandler.getEmployeesByName("Free");
System.out.println("\nResults from query: ");
while (rset.next()) {
System.out.println(rset.getInt(1) + " " +
rset.getString(2) + " " +
rset.getString(3) + " " +
rset.getString(4));
}

}

Greatly appreciate your response.
Regards,

Hieu