• 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

HttpServlet class

May 25, 2015 by javainterviewpoint Leave a Comment

The HttpServlet class extends the GenericServlet class and implements Serializable interface. It provides all the Http protocol supported methods such as  doGet(), doPost(), doHead(), doPut(), doDelete(), doOptions(), doTrace().

Methods of HttpServlet Class

  1. public void service(ServletRequest req,ServletResponse res): This method send the request to the protected service method by converting both the req and res to http type.
  2. protected void service(HttpServletRequest req, HttpServletResponse res): This method receives the request from the aboveservice method, and dispatches the request to the doXXX() method depending on the incoming http request type.
  3. protected void doGet(HttpServletRequest req, HttpServletResponse res): This method handles GET request, doGet() method we can send specific amount of data. If we use doGet () method data is shown in address bar. We must override doGet () method depending on type of request.
  4. protected void doPost(HttpServletRequest req, HttpServletResponse res): This method handles the POST request. Large amount of data can be sent using doPost() method. The data will not be visible in the address bar.
  5. protected void doHead(HttpServletRequest req, HttpServletResponse res): This method request header part of the GET request without the GET response body.
  6. protected void doOptions(HttpServletRequest req, HttpServletResponse res): This method handles the OPTIONS request.
  7. protected void doPut(HttpServletRequest req, HttpServletResponse res): This method is used to put files (i.e) uploading files on the server. If requests is incorrectly formated then it will return HTTP BAD_REQUEST error.
  8. protected void doTrace(HttpServletRequest req, HttpServletResponse res): This method is used for logging and debugging purpose. It can be used for testing the requested message. 
  9. protected void doDelete(HttpServletRequest req, HttpServletResponse res): This method handles the DELETE request. It deletes the files from the server.
  10. protected long getLastModified(HttpServletRequest req): This method returns the time when HttpServletRequest was last modified.

HttpServletExample.java

In this example we are creating a simple servlet class which extends the HttpServlet class. We will be providing the implementation of the doGet() method.

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
public class HttpServletExample extends HttpServlet{
 
	public void doGet(HttpServletRequest request, HttpServletResponse respon        se) throws IOException
        {
		PrintWriter out = response.getWriter();
		out.println("<html>");
		out.println("<body>");
		out.println("<h2>Http Servlet Example!!!</h2>");
        	out.println("</body>");
		out.println("</html>");	
	}
}

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"
	id="WebApp_ID" version="2.5">
     <display-name>HttpServletExample</display-name>
     <servlet>
         <servlet-name>HttpServletExample</servlet-name>
         <servlet-class>com.javainterviewpoint.HttpServletExample</servlet-class>
     </servlet>
     <servlet-mapping>
         <servlet-name>HttpServletExample</servlet-name>
         <url-pattern>/HttpServlet</url-pattern>
     </servlet-mapping>
</web-app>

Output

To run our HttpServletExample application hit on the below url

http://localhost:8080/ServletTutorial/HttpServlet

We will get the below output displayed in the browser

Http Servlet Example!!!

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
  • Difference Between GenericServlet and HttpServlet
  • welcome-file-list in web.xml of Servlets
  • Get Configuration information – ServletConfig
  • ServletContext Interface in Servlets
  • Obtaining HTTP Request Headers from HttpServletRequest
  • ServletRequest Interface – Servlets
  • ServletResponse Interface – Servlets
  • Get Query String from Servlet Request

Filed Under: J2EE, Java, Servlets Tagged With: HttpServlet, HttpServlet class, Servlet

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 ·