/*
* @(#)DataSourceList
*
* Copyright (c) 1999 Karl Moss. All Rights Reserved.
*
* You may study, use, modify, and distribute this software for any
* purpose provided that this copyright notice appears in all copies.
*
* This software is provided WITHOUT WARRANTY either expressed or
* implied.
*
* @author Karl Moss
* @version 1.0
* @date 17Feb99
*
*/
package javaservlets.nativeCode;
import javax.servlet.*;
import javax.servlet.http.*;
/**
* This servlet uses native code to gather a list of the
* current ODBC data sources.
*/
public class DataSourceList extends HttpServlet
{
/**
* Performs the HTTP GET operation
*
* @param req The request from the client
* @param resp The response from the servlet
*/
public void doGet(HttpServletRequest req,
HttpServletResponse resp)
throws ServletException, java.io.IOException
{
// Set the content type of the response
resp.setContentType("text/html");
// Get the PrintWriter to write the response
java.io.PrintWriter out = resp.getWriter();
// Create the header
out.println("");
out.println("
");
out.println("ODBC Data Source List");
out.println("");
out.println("");
out.println("ODBC Data Sources Available To Servlets " +
"Running in the Current Servlet Engine
");
out.println("
");
out.println("");
out.println("| Data Source Name | ");
out.println("Description |
|---|
");
int henv = 0;
try {
// Allocate an environment handle
henv = JavaToODBC.SQLAllocEnv();
}
catch (Exception ex) {
out.println("ERROR: Unable to allocate environment");
}
// Loop through the data sources until the end of file
// is reached
while (true) {
// Create a new DataSource object to hold the
// data source attributes (name, description)
DataSource ds = new DataSource();
boolean b = false;
try {
// Make a native ODBC call to get the next data source
// entry. The first call will return the first data source;
// any subsequent calls will return the next data source
b = JavaToODBC.SQLDataSources(henv, ds);
}
catch (Exception ex) {
ex.printStackTrace();
out.println("
ERROR: " + ex.getMessage());
break;
}
// SQLDataSources returns false if there are no more
// data sources
if (!b) {
break;
}
// Add this data source to the table
out.println("| " + ds.getName() +
" | " + ds.getDescription() + " |
");
}
if (henv != 0) {
try {
// Free the environment handle
JavaToODBC.SQLFreeEnv(henv);
}
catch (Exception ex) {
// Ignore any errors
}
}
// Wrap up
out.println("");
out.println("");
out.println("");
out.flush();
}
/**
* Initialize the servlet. This is called once when the
* servlet is loaded. It is guaranteed to complete before any
* requests are made to the servlet
*
* @param cfg Servlet configuration information
*/
public void init(ServletConfig cfg)
throws ServletException
{
super.init(cfg);
}
/**
*
Destroy the servlet. This is called once when the servlet
* is unloaded.
*/
public void destroy()
{
super.destroy();
}
}