Derby - Looking Up ClientDataSource Objects on File System

This section describes how to lookup a Derby JDBC ClientDataSource object in the file system using JNDI File System Service Provider.

Once the my CliendDataSource is stored on the file system through the JNDI directory service, I can get it back any time I need to create a connection to the Derby Network Server. What I need to do is:

I wrote the following sample program to retrieve my ClientDataSource object from the file system using the directory service via JNDI:

/* DerbyJndiLookup.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.util.*;
import java.sql.*;
import javax.sql.*;
import javax.naming.*;
public class DerbyJndiLookup {
  public static void main(String [] args) {
    Connection con = null;
    try {

// Starting the Directory service
      Hashtable env = new Hashtable();
      env.put(Context.INITIAL_CONTEXT_FACTORY,
        "com.sun.jndi.fscontext.RefFSContextFactory");
      env.put(Context.PROVIDER_URL, "file:/local/fscontext");
      Context ctx = new InitialContext(env);

// Looking up the DataSource object
      DataSource ds = (DataSource) ctx.lookup("DerbyTestDB");

// Getting a connection object
      con = ds.getConnection();

// Running a query
      Statement sta = con.createStatement();
      ResultSet res = sta.executeQuery(
        "SELECT * FROM HY_Address");
      System.out.println("List of Addresses: ");
      while (res.next()) {
         System.out.println(
           "  "+res.getInt("ID")
           + ", "+res.getString("StreetName")
           + ", "+res.getString("City"));
      }
      res.close();
      sta.close();

      con.close();

    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
    }
  }
}

Here is the output of compilation and execution of the program:

herong> java -cp .;derbyclient.jar;fscontext.jar;providerutil.jar \
   DerbyJndiLookup

List of Addresses:
  1, 5 Baker Road, Bellevue
  2, 25 Bay St., Hull
  3, 251 Main St., W. York

Table of Contents

 About This Book

 JDBC (Java Database Connectivity) Introduction

 JDK (Java SE) Installation

 Installing and Running Java DB - Derby

 Derby (Java DB) JDBC Driver

Derby (Java DB) JDBC DataSource Objects

 Derby - Connection with DataSource Objects

 Derby - Using ClientDataSource Directly

 Installing JNDI File System Service Provider

 Derby - Storing ClientDataSource Objects on File System

Derby - Looking Up ClientDataSource Objects on File System

 What Happens If Client JDBC DataSource JAR Is Missing?

 Java DB (Derby) - DML Statements

 Java DB (Derby) - ResultSet Objects of Queries

 Java DB (Derby) - PreparedStatement

 Summary of JDBC Drivers and Database Servers

 Using Connection Pool with JDBC

 Archived Tutorials

 References

 Full Version in PDF/EPUB