MySQL connection pooling (tomcat) problem

Oct 17, 2008 14:09:00

Hi all i just started learning servlets and i want to make a program in order to understand database connection pooling in tomcat.My problem is that when i run the servlet i created i get this error :

And that from tomcat log from netbeans :

.I configured tomcat server.xml file like this :
This is the resource reference i have in my web app web.xml file :

And this is my servlet class :

package org.DB;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.sql.*;
import javax.naming.*;
import javax.sql.*;
public class TestDB2 extends HttpServlet {
private Connection conn ;
private Statement stat ;
private ResultSet rs ;
private int counter;
private Object rsValue;
public void init() {
try {
InitialContext ctx = new InitialContext();
DataSource ds = (DataSource)ctx.lookup("java:comp/env/jdbc/phonebook_db");
conn = ds.getConnection();
}
catch(Exception e) {
e.printStackTrace();
}
}
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
try {
stat = conn.createStatement();
rs = stat.executeQuery("SELECT * FROM phones_table");
} catch (SQLException sqle) {
sqle.printStackTrace();
}
response.setContentType("text/html; charset=utf-8");
PrintWriter out = response.getWriter();
String docType = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 " + "Transitional//EN\">\n";
out.println(docType +"<HTML>\n" + "<HEAD><TITLE>PhoneBook entries</TITLE></HEAD>\n");
counter = 0;
try {
while (rs.next()) {
out.println("<h4>Entry no. " + (++counter) + "</h4>");
out.println("<table width=\"75%\" border=\"1\">");
out.println("<tr>\n"+ "<td width=\21%\"><b>LastName:</b></td>\n"+ "<td width=\"79%\">");
out.println((((rsValue = rs.getObject("LASTNAME"))==null || rs.wasNull())?
"":(rsValue.toString())));
out.println("</td>\n</tr>\n" + "<tr>\n"+
"<td width=\21%\"><b>FirstName:</b></td>\n"+ "<td width=\"79%\">");
out.println((((rsValue = rs.getObject("FIRSTNAME"))==null || rs.wasNull())?
"":(rsValue.toString())));
out.println("</td>\n"+ "</tr>\n"+
"<td width=\21%\"><b>Phone:</b></td>\n"+ "<td width=\"79%\">");
out.println((((rsValue = rs.getObject("PHONE"))==null || rs.wasNull())?
"":(rsValue.toString())));
out.println("</td>\n" + "</tr>\n" +
"</table>\n"+ "<br>\n<br>");
}
} catch (SQLException sqle) {
sqle.printStackTrace();
}
out.println("</body>\n"+
"</html>");
}
public void destroy() {
try {
rs.close();
stat.close();
conn.close();
} catch (SQLException sqle) {
sqle.printStackTrace();
}
}
}

Any suggestions?
[ October 17, 2008: Message edited by: Pavlos Chatzidimitriou ]

Oct 29, 2008 07:39:00

Hi,

try to create context.xml file udner META-INF directory.(at same level of WEB-INF)
in this file, enter:
<Context>your resource definition above where you put in server.xml</Context>

hope this helps.

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