Getting ServletContext init parameters that are defined in web.xml

In this example I am going to create some context parameter for performing database operation. The parameter names are
  a. DBUserName
  b. DBPassword
  c. DatabaseUrl
In servlet, I am going to get this details for performing database operation.

1. Create a new dynamic web project using eclipse.
2. Create a one new servlet and include the following code.
package com.controller;

import java.io.IOException;

import javax.servlet.ServletConfig;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

@WebServlet("/LoginController")

public class LoginController extends HttpServlet {

      private static final long serialVersionUID = 1L;

       public LoginController() {

        super();

    }

     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

            String userName = request.getParameter("userName");

            String password = request.getParameter("password");

            ServletConfig config = getServletConfig();

            ServletContext context = config.getServletContext();

            System.out.println("Context DB user name: " + context.getInitParameter("DBUserName"));

            System.out.println("Context DB password: " + context.getInitParameter("DBPassword"));

            System.out.println("Context DB URL: " + context.getInitParameter("DatabaseUrl"));

           //Database operation code goes here..!

      }

}

3. Update the web.xml file with following code.

<context-param>

      <param-name>DatabaseUrl</param-name>

      <param-value>http://10.10.10.10/TestDB</param-value>

  </context-param>

  <context-param>

      <param-name>DBUserName</param-name>

      <param-value>admin</param-value>

  </context-param>

  <context-param>

      <param-name>DBPassword</param-name>

      <param-value>admin</param-value>

  </context-param>

Once you run this servlet, the servlet will automatically get the database details from web.xml (context parameters).