Reading CSV on middle tier

Question

I have two applications where I need to read standard comma delimited text data. I would like to bind a VO to a csv as its data source, and am assuming that many have done this before. Is there a 'ready to use' extended class I can use?
In one app, I only need to read the rows in a table. Period.
In another I need to write the rows to a 9.2 database.
Any help, much appreciated.
-Nat

Answer 1

Nat,
By the Middle Tier I assume you mean an EJB bean (Session or Entity).
Read the J2EE Spec, Chapter 24.1.2, Programming Restrictions regarding File I/O. The spec states "An enterprise bean must not use the java.io package to attempt to access files and directories in the file system." The reason provided by the spec is "The file system API's are not well suited for business components to access data. Business components should use a resource manager API, such as JDBC, to store data."
My application needs to create database records and corresponding directories in the file system. I have succeeded in doing this by using JNDI File System Service provider as sketched below:
***** Session Bean ******
package myco.i.Demo.ejb;
import javax.ejb.SessionBean;
import myco.i.Demo.dao.DocDAO;
public class DemoFacadeBean implements SessionBean
{ private   DocDAO aDocDao;
public void ejbCreate()
{  aDocDao = new DocDAO();  }
public void addDoc(DocDto theDoc)
throws DocDAOException
{  DocDAO.addDoc(theDoc);  }
***** DAO Code ******
package myco.i.Demo.dao;
import myco.i.Demo.dto.DocDto;
public class DocDAO {
private Context fsCtx;
// Constructor
public DocDAO()
super();
     // Set up the initial File System context
     Hashtable env = new Hashtable(11);
     env.put(Context.INITIAL_CONTEXT_FACTORY,
     "com.sun.jndi.fscontext.RefFSContextFactory");
     env.put(Context.PROVIDER_URL, "file : /Demo");
     try { fsCtx = new InitialContext(env); }
     catch {...}
// Business methods
public void addDoc(aDoc)
throws DocDAOException
Context newDir = fsCtx.createSubcontext(aDoc.getLocation());
... JDBC Code to create new database record ...
To make this work I had to copy the JNDI File System provider classes (fscontext.jar, providerutil.jar)into the JRE (inherently insecure if someone hacks your site). I don't know if this is any better then setting the security on your app server to allow Java.io.* (JNDI has some overhead).
You can use java.io from within the web container (jsp's/Servelets), but you loose a little bit of transaction processing. I may end up choosing this direction to stay within the spec.
Hope this helps.
Jake