• Java
    • JAXB Tutorial
      • What is JAXB
      • JAXB Marshalling Example
      • JAXB UnMarshalling Example
  • Spring Tutorial
    • Spring Core Tutorial
    • Spring MVC Tutorial
      • Quick Start
        • Flow Diagram
        • Hello World Example
        • Form Handling Example
      • Handler Mapping
        • BeanNameUrlHandlerMapping
        • ControllerClassNameHandlerMapping
        • SimpleUrlHandlerMapping
      • Validation & Exception Handling
        • Validation+Annotations
        • Validation+ResourceBundle
        • @ExceptionHandler
        • @ControllerAdvice
        • Custom Exception Handling
      • Form Tag Library
        • Textbox Example
        • TextArea Example
        • Password Example
        • Dropdown Box Example
        • Checkboxes Example
        • Radiobuttons Example
        • HiddenValue Example
      • Misc
        • Change Config file name
    • Spring Boot Tutorial
  • Hibernate Tutorial
  • REST Tutorial
    • JAX-RS REST @PathParam Example
    • JAX-RS REST @QueryParam Example
    • JAX-RS REST @DefaultValue Example
    • JAX-RS REST @Context Example
    • JAX-RS REST @MatrixParam Example
    • JAX-RS REST @FormParam Example
    • JAX-RS REST @Produces Example
    • JAX-RS REST @Consumes Example
    • JAX-RS REST @Produces both XML and JSON Example
    • JAX-RS REST @Consumes both XML and JSON Example
  • Miscellaneous
    • JSON Parser
      • Read a JSON file
      • Write JSON object to File
      • Read / Write JSON using GSON
      • Java Object to JSON using JAXB
    • CSV Parser
      • Read / Write CSV file
      • Read/Parse/Write CSV File – OpenCSV
      • Export data into a CSV File
      • CsvToBean and BeanToCsv – OpenCSV

JavaInterviewPoint

Java Development Tutorials

Obtaining HTTP Request Headers from HttpServletRequest

June 15, 2015 by javainterviewpoint Leave a Comment

In this article we will learn how to get the HTTP Request Headers via HttpServletRequest, The HTTP request which a client browser sends to the server includes HTTP request headers with  some important information, such as cookies and the referer. You can access these headers from the HttpServletRequest object passed to a doxxx method.In this example we will get all the header information using the getHeaderNames() method of the HttpServletRequest interface which will return Enumeration of the all the header information.

RequestHeaderExample.java

package com.javainterviewpoint;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;

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

public class RequestHeaderExample  extends HttpServlet 
{
    public void doGet(HttpServletRequest request, HttpServletResponse response) 
    throws ServletException, IOException 
    {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        Enumeration enumeration = request.getHeaderNames();
        while (enumeration.hasMoreElements()) 
        {
             String header = (String) enumeration.nextElement();
             out.println(header + ": " + request.getHeader(header) + "
");
        }
    }
}

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%20http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
 <display-name>ServletsTutorial</display-name>
 <servlet>
     <servlet-name>RequestHeaderExample</servlet-name>
     <servlet-class>com.javainterviewpoint.RequestHeaderExample</servlet-class>
 </servlet>
 <servlet-mapping>
     <servlet-name>RequestHeaderExample</servlet-name>
     <url-pattern>/RequestHeaderExample</url-pattern>
 </servlet-mapping>
</web-app>

When we run the above code we will get the below output

URL : http://localhost:8080/ServletsTutorial/RequestHeaderExample

Output:

accept: image/jpeg, application/x-ms-application, image/gif, application/xaml+xml, image/pjpeg, application/x-ms-xbap, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*
accept-language: en-US
cache-control: no-cache
user-agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)
accept-encoding: gzip, deflate
host: localhost:8080
connection: Keep-Alive

Instead of getting all the header, we can get the value of a particular header by using getHeader() method. We will modify the above code a bit.

package com.javainterviewpoint;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;

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

public class RequestHeaderExample  extends HttpServlet 
{
    public void doGet(HttpServletRequest request, HttpServletResponse response) 
    throws ServletException, IOException 
    {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.println("User Agent : "+request.getHeader("user-agent"));
    }
}

Hit on the URL : http://localhost:8080/ServletsTutorial/RequestHeaderExample

Output:

User Agent : Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)

Other interesting articles which you may like …

  • Difference between ServletConfig and ServletContext
  • How to change Tomcat default port from 8080 to Some Other?
  • Life Cycle of a Servlet
  • JSP Custom tags
  • Access body of Custom Tag in JSP
  • Attributes In Jsp Custom Tag
  • Running Your First Servlet Application
  • Servlet Interface
  • GenericServlet class
  • Difference Between GenericServlet and HttpServlet
  • welcome-file-list in web.xml of Servlets
  • Get Configuration information – ServletConfig
  • ServletContext Interface in Servlets
  • ServletRequest Interface – Servlets
  • ServletResponse Interface – Servlets
  • Get Query String from Servlet Request

Filed Under: J2EE, Java, Servlets Tagged With: Attributes, Cookies, Filters, Http Request Headers, HttpServletRequest, HttpSession, Listeners, Servlet Config, Servlet Context, Servlet Events, Servlet Life cycle, Servlet request, Servlet response, Servlet tutotials, Session

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

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

Java Basics

  • JVM Architecture
  • Object in Java
  • Class in Java
  • How to Set Classpath for Java in Windows
  • Components of JDK
  • Decompiling a class file
  • Use of Class.forName in java
  • Use Class.forName in SQL JDBC

Oops Concepts

  • Inheritance in Java
  • Types of Inheritance in Java
  • Single Inheritance in Java
  • Multiple Inheritance in Java
  • Multilevel Inheritance in Java
  • Hierarchical Inheritance in Java
  • Hybrid Inheritance in Java
  • Polymorphism in Java – Method Overloading and Overriding
  • Types of Polymorphism in java
  • Method Overriding in Java
  • Can we Overload static methods in Java
  • Can we Override static methods in Java
  • Java Constructor Overloading
  • Java Method Overloading Example
  • Encapsulation in Java with Example
  • Constructor in Java
  • Constructor in an Interface?
  • Parameterized Constructor in Java
  • Constructor Chaining with example
  • What is the use of a Private Constructors in Java
  • Interface in Java
  • What is Marker Interface
  • Abstract Class in Java

Java Keywords

  • Java this keyword
  • Java super keyword
  • Final Keyword in Java
  • static Keyword in Java
  • Static Import
  • Transient Keyword

Miscellaneous

  • newInstance() method
  • How does Hashmap works internally in Java
  • Java Ternary operator
  • How System.out.println() really work?
  • Autoboxing and Unboxing Examples
  • Serialization and Deserialization in Java with Example
  • Generate SerialVersionUID in Java
  • How to make a class Immutable in Java
  • Differences betwen HashMap and Hashtable
  • Difference between Enumeration and Iterator ?
  • Difference between fail-fast and fail-safe Iterator
  • Difference Between Interface and Abstract Class in Java
  • Difference between equals() and ==
  • Sort Objects in a ArrayList using Java Comparable Interface
  • Sort Objects in a ArrayList using Java Comparator

Follow

  • Coding Utils

Useful Links

  • Spring 4.1.x Documentation
  • Spring 3.2.x Documentation
  • Spring 2.5.x Documentation
  • Java 6 API
  • Java 7 API
  • Java 8 API
  • Java EE 5 Tutorial
  • Java EE 6 Tutorial
  • Java EE 7 Tutorial
  • Maven Repository
  • Hibernate ORM

About JavaInterviewPoint

javainterviewpoint.com is a tech blog dedicated to all Java/J2EE developers and Web Developers. We publish useful tutorials on Java, J2EE and all latest frameworks.

All examples and tutorials posted here are very well tested in our development environment.

Connect with us on Facebook | Privacy Policy | Sitemap

Copyright ©2023 · Java Interview Point - All Rights Are Reserved ·