Home » Enterprise Java » servlet » Get/Set init Parameters in Servlet

About Ilias Tsagklis

Ilias is a software developer turned online entrepreneur. He is co-founder and Executive Editor at Java Code Geeks.

Get/Set init Parameters in Servlet

In this example we are going to see how to get/set init parameters in a Servelt. Using init parameters you can specify several important aspects of your servlets that are going to be handled during requests service.

In short, to get/set init Parameters in Servlet you should:

  • Create public void init() function on your servlet.
  • Call getServletConfig().getInitParameterNames()
  • Use put(initParamName, initParamValue) to put parameters in your init parameter map.
  • In your doGet method use initParamsMap.entrySet().iterator() to get an Iterator an iterate through init parameters.
 
Let’s see the code snippets that follow:
package com.javacodegeeks.snippets.enterprise;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class GetSetInitParametersInServlet extends HttpServlet {

	private static final long serialVersionUID = -2128122335811219481L;

	private String paramName;
	private String paramValue;

	public void init() throws ServletException {
		paramName = "myparam";
		paramValue = getServletConfig().getInitParameter(paramName);
	}

	public void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException {

		PrintWriter out = res.getWriter();
		res.setContentType("text/plain");

		out.write(paramName);
		out.write(" = ");
		out.write(paramValue);

		out.close();
	}

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
  version="2.5">

	<display-name>JCG Snippets Web Project</display-name>

	<servlet>
		<servlet-name>JCG Snippets Application</servlet-name>
		<servlet-class>com.javacodegeeks.snippets.enterprise.GetSetInitParametersInServlet</servlet-class>
		<init-param>
			<param-name>myparam</param-name>
			<param-value>myvalue</param-value>
		</init-param>
	</servlet>

	<servlet-mapping>
		<servlet-name>JCG Snippets Application</servlet-name>
		<url-pattern>/jcgservlet</url-pattern>
	</servlet-mapping>

</web-app>

URL:

http://myhost:8080/jcgsnippets/jcgservlet

Output:

myparam = myvalue

This was an example on how to get/set init Parameters in Servlet.

Do you want to know how to develop your skillset to become a Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you our best selling eBooks for FREE!

 

1. JPA Mini Book

2. JVM Troubleshooting Guide

3. JUnit Tutorial for Unit Testing

4. Java Annotations Tutorial

5. Java Interview Questions

6. Spring Interview Questions

7. Android UI Design

 

and many more ....

 

Receive Java & Developer job alerts in your Area

I have read and agree to the terms & conditions

 

Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

0 Comments
Inline Feedbacks
View all comments