jdbc value retrieval from a bean and then from a jsp

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Posts: 6

posted 22 years ago

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hello everyone
i am trying to call database values from a bean and then ultimately want to display them from a jsp but the error "java.sql.SQLException: no data found" arising everytime.
what to do? please help. my database name is ppp.mdb and it is placed in d:\jakarta-tomcat-4.0-b5\examples\jsp\ppp.mdb
in here, i have two tables with the name a)conference and b)shuttles
in the conference table, i have four field which i am writing in the following order: field_name:field_type
1)ID:integer
2)city:String
3)airport:String
4)seats:integer
the ConnectionBean class code is the same that i have posted previously
however i have changed conference1.jsp a bit.
so the code of conference1.jsp is pasted here.
i want to tell that i have tomcat server and the path for both .java and .jsp is as follows:
d:\jakarta-tomcat-4.0-b5\webapps\examples\web-inf\classes\babaji\ch_7\ConnectionBean.java
d:\jakarta-tomcat-4.0-b5\webapps\examples\jsp\conference1.jsp

//conference1.jsp starts from here
<%@ page import="java.sql.*"%>
<jsp:useBean id="connection" class="babaji.ch_7.ConnectionBean" scope="session" />
<html>
<body>
<center>
<font size="+2" face="arial" ><b>Conference Registration</b></font>
<form action="shuttle.jsp" method="post">
<table border="1" bgcolor="tan" width="50%" align="center">
<tr><td><table border="0" bgcolor="white" cellspacing="0" width="100%">
<tr bgcolor="tan">
<th> </th><th>City</th><th>Tickets Remaining</th></tr>
<%
String sql = "select * from conference";
ResultSet results = connection.executeQuery(sql);
while(results.next())
{
    if(results.getInt("seats") > 0)
    {
    %>
<td>
<input type="radio" name="show" value="<%= results.getInt("ID") %>"</td>
</td>
    <%
    }
    %>
<td><%= results.getString("city") %> </td>
<td align="center"><%= results.getInt("seats") %>
</td>
</tr>
<%
}
%>
</table>
</td></tr></table>
<p>
<input type="submit" value="Next Generation (choose shuttle)">
</form>
</center>
</body>
</html>
//conference1.jsp ends here

//ConnectionBean.java starts from here
package babaji.ch_7;
import java.sql.*;
import javax.servlet.http.*;
public class ConnectionBean implements HttpSessionBindingListener
{
    private Connection con;
    private Statement stat;
    private static final String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
    private static final String dbURL = "jdbc:odbc:project4";
public ConnectionBean()
{
    try
    {
        Class.forName(driver);
        con = DriverManager.getConnection(dbURL);
        stat = con.createStatement();
    }
    catch(ClassNotFoundException e)
    {}
    catch(SQLException e)
    {}
}
public void commit() throws SQLException
{
    con.commit();
}
public void rollback() throws SQLException
{
    con.rollback();
}
public void setAutoCommit(boolean autoCommit) throws SQLException
{
    con.setAutoCommit(autoCommit);
}
public ResultSet executeQuery(String sql) throws SQLException
{
    return stat.executeQuery(sql);
}
public int executeUpdate(String sql) throws SQLException
{
    return stat.executeUpdate(sql);
}
public void valueBound(HttpSessionBindingEvent event)
{
    System.err.println("ConnectionBean: in the valueBound method");
    try
    {
        if(con == null || con.isClosed())
        {
 
            con = DriverManager.getConnection(dbURL);
            stat = con.createStatement();
        }
    }
    catch(SQLException e)
    {
        con = null;
    }
}
public void valueUnbound(HttpSessionBindingEvent event)
{
    try
    {
        con.close();
    }
    catch(SQLException e)
    {}
    finally
    {
        con = null;
    }
}
protected void finalize()
{
    try
    {
        con.close();
    }
    catch(SQLException e)
    {}
}
}
//ConnectionBean.java ends here

please help and let me know the solution for this error
thanks, wating anxiously for the reply
bye
take care
from Shehzad Khan
[ Edited by Dave to format code and fix UBB smilies ]
[ January 31, 2002: Message edited by: David O'Meara ]

Napa Sreedhar

Ranch Hand

Posts: 62

posted 22 years ago

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Everrthing seems to be fine...
But a look up.. Chek the dbURL in your connection bean class... Is it OK ?
Napa

Napa Sreedhar

Ranch Hand

Posts: 62

posted 22 years ago

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And one more suggestion use PreparedStatement in your bean class.
I heard some where that Statement doesn't work out for regular expressions.
Napa

Shehzad Khan

Greenhorn

Posts: 6

posted 22 years ago

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hello everybody
thanks a lot mr.napa sreedher, for your kind suggestion. but still no use.
i kindly request you mr. napa and also request to anyone that you run this code which i have given here on your pc if you have some time and let me know whether it is running alright or not.
ok take care
bye
from shehzad khan

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