Tomcat can't find a JDBC JNDI resource

[Aodhan Hoffman]

I'm trying to write a tag that takes form input and inserts it into a database. (Perhaps not clean, but I'm playing around. )

I'm using Netbeans 4.x ( which includes Tomcat 5.5.x ).

WHen I submit the form I get the following error ( truncated )

 nex
Name jdbc is not bound in this Context
Name jdbc is not bound in this Context
Error!
 
org.apache.naming.NamingContext.lookup(NamingContext.java:769)
org.apache.naming.NamingContext.lookup(NamingContext.java:152)
org.apache.naming.factory.ResourceLinkFactory.getObjectInstance(ResourceLinkFactory.java:96)
javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:301)
org.apache.naming.NamingContext.lookup(NamingContext.java:792)
org.apache.naming.NamingContext.lookup(NamingContext.java:139)
org.apache.naming.NamingContext.lookup(NamingContext.java:780)
org.apache.naming.NamingContext.lookup(NamingContext.java:152)
net.terran.JobTracker.MySQLDBITag.initDataSource(MySQLDBITag.java:131)
net.terran.JobTracker.MySQLDBITag.doTag(MySQLDBITag.java:71)
org.apache.jsp.table_jsp._jspx_meth_jobber_MySQLDBITag_0(table_jsp.java:316)
org.apache.jsp.table_jsp._jspService(table_jsp.java:137) 

I read the JNDI HOW-TO, other Tomcat documents relating to JDBC and JNDI naming, as well as other research. The result is a slightly mixed approach that closely matches the recommendations from the HOW-TO. Comparing what I have to the HOW-TO, I don't know where the issue is.

Here's the server.xml entry:

     <Resource
      name="jdbc/poolDB"
      auth="Container"
      type="javax.sql.DataSource"
      driverClassName="org.gjt.mm.mysql.Driver"
      password="forster"
      maxIdle="2"
      maxWait="5000"
      username="root"
      url="jdbc:mysql://localhost:3306/jobtracker"
      maxActive="4"/>
  </GlobalNamingResources> 

Here's the context.xml ( within the webapp file system ) entry :

  <?xml version="1.0" encoding="UTF-8"?>
<Context path="/JobTracker">
  <Logger className="org.apache.catalina.logger.FileLogger" prefix="JobTracker." suffix=".log" timestamp="true"/>
  <ResourceLink name="jdbc/poolDB" type="javax.sql.DataSource" global="jdbc/poolDB"/>
</Context>

Here's the deployment descriptor for the webapp:

 
     <resource-ref>
<description>Tomcat DBCP</description>
        <res-ref-name>jdbc/poolDB</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
    </resource-ref>
 

and finally the code that's supposed to be initializing the DataSource

 
    private void initDataSource() throws javax.naming.NamingException, java.sql.SQLException, java.io.IOException
    {
Context ectx = null;
try
{
    ictx = new javax.naming.InitialContext();
    ectx = (Context)ictx.lookup("java:comp/env");
            ds = (javax.sql.DataSource)ectx.lookup("jdbc/poolDB");
}
catch ( NullPointerException npex )
{
    JspWriter out=getJspContext ().getOut ();
    out.write("npex");
    
    out.write( ectx.toString () );
    out.write( getJspContext().getAttribute ("datasource").toString() );
    
}
connect = ds.getConnection();
    }
 

The line it specifically hiccups on is this one:

ds = (javax.sql.DataSource)ectx.lookup("jdbc/poolDB");  

Any input would be appreciated, thanks!

[Craig Jackson]

No apparent syntax errors jump out.

So I would suggest a couple things...

1. When Tomcat starts up, check the log/console to verify that your configurations did not generate any errors.

2. Where in your web application did you place the context.xml file?

[Aodhan Hoffman]

The only start up errors I get has something to do with tomcat already using the port it wants to use. ( A perplexing error that doesn't seem to stop tomcat from launching. )

The context.xml file is in webapps/jobtracker/META-INF/context.xml.

For sanity, I quit NetBeans, went on with life for a couple of hours, read your post and tried again. THis time, it magically worked. NetBeans itself, not just Tomcat, must have needed a restart. An annoying lesson. I need to find out how to get netbeans to use MY tomcat installation...but that's a separate issue.

Regardless, I appreciate your time verifying my configuration.

Now, I am getting a 'connection pool exhausted' error on submitting the form.

 
Cannot get a connection, pool exhausted
 
org.apache.tomcat.dbcp.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:103)
org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:540)
net.terran.JobTracker.MySQLDBITag.initDataSource(MySQLDBITag.java:146)
net.terran.JobTracker.MySQLDBITag.doTag(MySQLDBITag.java:69)
org.apache.jsp.table_jsp._jspx_meth_jobber_MySQLDBITag_0(table_jsp.java:316)
org.apache.jsp.table_jsp._jspService(table_jsp.java:137)
...
 

The function in question is this:

    private void initDataSource() throws javax.naming.NamingException, java.sql.SQLException, java.io.IOException
    {
Context ectx = null;
try
{
    ictx = new javax.naming.InitialContext();
    ectx = (Context)ictx.lookup("java:comp/env");
            ds = (javax.sql.DataSource)ectx.lookup("jdbc/poolDB");
}
catch ( NullPointerException npex )
{
    JspWriter out=getJspContext ().getOut ();
    out.write("npex");
    
    out.write( ectx.toString () );
    out.write( getJspContext().getAttribute ("datasource").toString() );
    
}
connect = ds.getConnection();
    }
  

The specific line is:

 
connect = ds.getConnection();
 

So I went back and confirmed the related information was specified in the server.xml file:

    <Resource
      name="jdbc/poolDB"
      auth="Container"
      type="javax.sql.DataSource"
      driverClassName="org.gjt.mm.mysql.Driver"
      password="forster"
      maxIdle="2"
      maxWait="5000"
      username="root"
      url="jdbc:mysql://localhost:3306/jobtracker"
      maxActive="4"/>
  

Now there should be more than enough connections. However, I am doing a batch. (One form entry is still only one query though. ) Could this be a problem? Is there somewhere else I should look for trouble?

THanks again.

[Craig Jackson]

How are you closing your connections, thus returning the connection back to the pool?


Is your connection object stored in a instance variable? I usually try to acquire a connection, run my query(s), close connection, resultsSet(s) all withing one method call.

[Aodhan Hoffman]

Based on your suggestion Craig I rooted around and found the problem. I was stumbling over the connection pool concerns, just trying to get them to work, I missed the more basic JDBC related errors. Your mention regarding the Connection object got me back on track.

Many thanks for your time!