help in my first DBCP

[manish sahni]

hi,

I have created a DBCP and it is showing me error:
The code is as follows:-

DBTest.java

 package foo;

import javax.naming.*;
import javax.sql.*;
import java.sql.*;

public class DBTest {

  String foo = "Not Connected";
  int bar = -1;

  public void init() {
    try{
      Context ctx = new InitialContext();
      if(ctx == null )
          throw new Exception("Boom - No Context");

      DataSource ds =
            (DataSource)ctx.lookup(
               "java:comp/env/jdbc/upl_db");

      if (ds != null) {
        Connection conn = ds.getConnection();

        if(conn != null)  {
            foo = "Got Connection "+conn.toString();
            Statement stmt = conn.createStatement();
            ResultSet rst =
                stmt.executeQuery(
                  "select id, foo, bar from testdata");
            if(rst.next()) {
               foo=rst.getString(2);
               bar=rst.getInt(3);
            }
            conn.close();
        }
      }
    }catch(Exception e) {
      e.printStackTrace();
    }
 }

 public String getFoo() { return foo; }
 public int getBar() { return bar;}
}
  

context.xml:-

  <?xml version="1.0" encoding="UTF-8"?>

<Context path="/DataSourceExample" docBase="DataSourceExample" debug="5" reloadable="true" crossContext="true">
<ResourceLink global="jdbc/upl_db" name="jdbc/upl_db" type="javax.sql.DataSource"/>
<Logger className="org.apache.catalina.logger.FileLogger"
             prefix="localhost_DataSourceExample_log." suffix=".txt"
             timestamp="true"/>
<Resource name="jdbc/upl_db"
               auth="Container"
               scope="Shareable"
               type="javax.sql.DataSource"/>
               <ResourceParams name="jdbc/upl_db">
    <parameter>
      <name>factory</name>
      <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
    </parameter>
     <!-- Maximum number of dB connections in pool. Make sure you
         configure your mysqld max_connections large enough to handle
         all of your db connections. Set to -1 for no limit.
         -->
    <parameter>
      <name>maxActive</name>
      <value>100</value>
    </parameter>
       <!-- Maximum number of idle dB connections to retain in pool.
         Set to 0 for no limit.
         -->
    <parameter>
      <name>maxIdle</name>
      <value>30</value>
    </parameter>
     <!-- Maximum time to wait for a dB connection to become available
         in ms, in this example 10 seconds. An Exception is thrown if
         this timeout is exceeded.  Set to -1 to wait indefinitely.
         -->
    <parameter>
      <name>maxWait</name>
      <value>10000</value>
    </parameter>
 <!-- MySQL dB username and password for dB connections  -->
    <parameter>
     <name>username</name>
     <value>root</value>
    </parameter>
    <parameter>
     <name>password</name>
     <value>root</value>
    </parameter>
     <!-- Class name for mm.mysql JDBC driver -->
    <parameter>
       <name>driverClassName</name>
       <value>org.gjt.mm.mysql.Driver</value>
    </parameter>
 <!-- The JDBC connection url for connecting to your MySQL dB.
         -->
    <parameter>
      <name>url</name>
      <value>jdbc:mysql://localhost:3306/upl_db</value>
    </parameter>
  </ResourceParams>
</Context>

  

web.xml:

   <?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
    <resource-ref>
        <description>MySql Test App</description>
        <res-ref-name>jdbc/upl_db</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
        <res-sharing-scope>Shareable</res-sharing-scope>
    </resource-ref>
</web-app>
 

Jsp file:-

  <%-- 
    Document   : index
    Created on : Jan 1, 2002, 1:46:41 AM
    Author     : Administrator
--%>

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>DBCP Test Code</title>
    </head>
    <body>
    <% foo.DBTest tst = new foo.DBTest();
        tst.init();
    System.out.println("foo is   "+tst.getFoo());
    System.out.println("Bar is   "+tst.getBar());
    %>

        <h2>Results</h2>
    Foo <%= tst.getFoo() %><br/>
    Bar <%= tst.getBar() %>


    </body>
</html>
  

Error it is showing is:-

 INFO: Container org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/DataSourceExample] has already been started
javax.naming.NameNotFoundException: Name jdbc is not bound in this Context
        at org.apache.naming.NamingContext.lookup(NamingContext.java:770)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:153)
        at org.apache.naming.factory.ResourceLinkFactory.getObjectInstance(ResourceLinkFactory.java:97)
        at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:304)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:793)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:140)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:140)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:140)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:153)
        at org.apache.naming.SelectorContext.lookup(SelectorContext.java:137)
        at javax.naming.InitialContext.lookup(InitialContext.java:392)
        at foo.DBTest.init(DBTest.java:18)
        at org.apache.jsp.index_jsp._jspService(index_jsp.java:67)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
        at java.lang.Thread.run(Thread.java:619)
foo is   Not Connected
Bar is   -1   

Please let me know the root cause..

[Prabhakar Reddy Bokka]

Better you post this query in JDBC group.