RE: java error in database access

[Randy Layman <ra...@aswethink.com>]

	Your problem is the JDBC-ODBC Bridge.  Search through Sun's
BugParade for more detailed information, but basically the bridge is not
thread-safe and concurrent access will cause Page Fault/GPF/Dr Watson errors
on Windows based computers.

	Randy

> -----Original Message-----
> From: Dwaipayan [mailto:babua_007@rediffmail.com]
> Sent: Thursday, July 05, 2001 3:37 PM
> To: tomcat-user@jakarta.apache.org
> Subject: java error in database access
> 
> 
> 
> i have been facing a problem in tomcat which i could not 
> solve may be due to being a "first time user" . i will be 
> pleased if u could tell me the source of this problem.
> i have a login page where the user enters username and 
> password in 2 text fields(user & pwd).the form action leads 
> to login.jsp file.if  both are found in the table "login" 
> located in Oracle8.0.4(personal edition), then the user is 
> greeted by his username. else error msg is shown.when i used 
> JdbcOdbcDriver the output was as expected.but immediately 
> after the output page was displayed,an illegal operation 
> msgbox was shown by java.this error does not occur 
> sometimes.but whenever i stop tomcat and restart it,and acces 
> my login page the error appears again.the error looks like 
> the following:
> 
> [
> JAVA caused an invalid page fault in
> module <unknown> at 0000:08412f90.
> Registers:
> EAX=083105d8 CS=0177 EIP=08412f90 EFLGS=00010297
> EBX=08310908 SS=017f ESP=050dfd2c EBP=050dfd4c
> ECX=00000000 DS=017f ESI=08310140 FS=3ca7
> EDX=08310140 ES=017f EDI=00000000 GS=0000
> Bytes at CS:EIP:
> 
> Stack dump:
> 1f7025d1 004151d0 00000000 01950000 007b1ec0 00679470 
> 00000000 00000000 050dfda4 1f702505 08310140 00000000 
> 00000010 019512e8 007b1ec0 50472958 
> ]
> my classpath has tomcat_home,java_home,and 
> c:\jdk1.2.2\lib\tools.jar set appropriately
> i am using Windows98 machine with 64mb ram,433mhz and with 
> initial memory set to 3072(thru dos window properties--memory tab).
> 
> i have tried in debugging by putting System.out.println() 
> statements but to no avail.
> 
> i am enclosing the login.jsp file i used.
> eagerly awaiting ur comments.
> 
> login.jsp:
> 
> <%@ page session="true" 
> import="java.sql.*,sun.jdbc.odbc.*,java.io.*" %>
> 
> 
> <% 
> String s1=request.getParameter("user");
> String s2=request.getParameter("pwd");
> String upwd=null;
> try{
> 
> if(s1.length()==8 &&  s2.length()==6)
> {
> 	System.out.println("loading driver");
>                  Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
> 		System.out.println("creating connection");
>                 Connection 
> con=DriverManager.getConnection("jdbc:odbc:login","scott","tiger");
> 		System.out.println("creating statement");
>                Statement stmt=con.createStatement();
> 	        
> 		System.out.println("executing query");
>                 ResultSet rs=stmt.executeQuery("select 
> password from login where username='"+ s1+"'");
> 		System.out.println("checking if rs is null");
>                 if(rs!=null)
> 	{
> 				System.out.println("while rs exists");
> 			while(rs.next())
>                 			{
> 					
> System.out.println("retrieving password");
> 				upwd=rs.getString("password");
> 			}
> 	}
> 		System.out.println("closing connection");
>            	con.close();
> 			System.out.println("checking if upwd is null"); 
> 		if(upwd!=null)
> 		{
> 				System.out.println("checking if 
> upwd=s2");
> 			if(s2.equals(upwd))
> 			{
> 					System.out.println("if 
> upwd=s2");
>                         			
> out.println("Welcome Back to this site "+s1);
> 			}
>                          
>                         
>                  	 		else
> 		 	{
> 	     				System.out.println("if 
> upwd not equal to s2");
> 	    		            	out.println("Incorrect 
> password");
> 			}
> 	     
>                 		}
> 	                else
>            		{
> 				System.out.println("if upwd is 
> null");     
>                 			out.println("Incorrect 
> username ");
> 		}
>                 
>                 
>                 
>                 
> 
> 
> }
> else
> {
> 		System.out.println("if entered 
> username/password are not valid");
> 	out.println("Invalid no. of characters in username/password");
> }
> }
> catch(Exception ex){System.out.println("inside catch"+ex);}
> System.out.println("end of jsp");
> 
>  %>
> 
> 
> 
> Dwaipayan Datta Ray (call me Ray)
> babua_007@rediffmail.com
> 
> 
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