Java Programming Code Examples
Java > Servlets Code Examples
Accessing servlet jndi environment variables
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Accessing servlet jndi environment variables
package com.ack.web.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* It is better to use environment variables within a J2EE
* context for values that can be changed a deployment time
* instead of Context attributes within the web.xml. This
* way you don't have to update the web.xml to change the
* values.
*
*
<env-entry>
<description>the guy responsible for this site</description>
<env-entry-name>webmaster</env-entry-name>
<env-entry-value>[email protected]</env-entry-value>
<env-entry-type>java.lang.String</env-entry-type>
</env-entry>
*/
public class AccessingServletJndiEnvironmentVariables extends HttpServlet {
public void doGet( HttpServletRequest req, HttpServletResponse res )
throws ServletException, IOException {
res.setContentType( "text/html" );
PrintWriter pw = res.getWriter();
String webMaster = null;
try {
// get a handle on the JNDI root context
Context ctx = new InitialContext();
// and access the environment variable for this web component
webMaster = (String) ctx.lookup( "java:comp/env/webmaster" );
}
catch( NamingException ex ) {
ex.printStackTrace();
}
pw.println( "the web master is -> " + webMaster );
}
}
