Servlet Tutorials

public void setAttribute(String name,Object object):It is sets the given object in the application scope.
public Object getAttribute(String name):It is returns the attribute for the specified name.
public Enumeration getInitParameterNames():It is returns the names of the context's initialization parameters as an Enumeration of String objects.
public void removeAttribute(String name):It is removes the attribute with the given name from the servlet context.

Example of ServletContext to set and get attribute

Servlet1.java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class DemoServlet1 extends HttpServlet{
public void doGet(HttpServletRequest req,HttpServletResponse res)
{
try{
res.setContentType("text/html");
PrintWriter out=res.getWriter();
ServletContext context=getServletContext();
context.setAttribute("company","IBM");
out.println("Welcome to first servlet");
out.println("<a href='servlet2'>visit</a>");
out.close();
}catch(Exception e){out.println(e);}
}}

Servlet2.java

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class DemoServlet2 extends HttpServlet{
public void doGet(HttpServletRequest req,HttpServletResponse res)
{
try{
res.setContentType("text/html");
PrintWriter out=res.getWriter();
ServletContext context=getServletContext();
String n=(String)context.getAttribute("company");
out.println("Welcome to "+n);
out.close();
}catch(Exception e){out.println(e);}
}}

web.xml

<web-app>
<servlet>
<servlet-name>s1</servlet-name>
<servlet-class>DemoServlet1</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>s1</servlet-name>
<url-pattern>/servlet1</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>s2</servlet-name>
<servlet-class>DemoServlet2</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>s2</servlet-name>
<url-pattern>/servlet2</url-pattern>
</servlet-mapping>
</web-app>