Servlets introduction for beginners with explanation, examples and screenshots
Communication between the Servlets is an important task to the Programmer. To achieve this, we studied reading private data of a servlet and reading global data by all servlets. Now let us see how to pass data between two servlets (one-to-one) and for this Servlet API comes with javax.servlet.RequestDispatcher interface. When to use RequestDispatcher interface? …
The javax.servlet.RequestDispatcher interface comes with only two methods of include() and forward(). These methods are discussed very clearly with example code, illustrative figures and explanation in RequestDispatcher include Example and RequestDispatcher forward Example. It is advised to go through these two programs before learning the differences. RequestDispatcher is used whenever the Programmer would like dispatch …
16 Differences include vs forward Decide when to use which? Read More »
For easy understanding, the notes is given in Question/Answer format. 1. What is a Session in Servlets? The interactive time between client and server on a single connection is known as a session. Or The period of time between connection establishment and connection closing between client and server is known as a session. Or Session …
What is Session, Session Tracking, Session Management? Read More »
Before reading this, it is advised to read the nature of HTTP protocol and what are session, session tracking and JSESSIONID. To maintain HTTP session in Servlets, the Java API comes with javax.servlet.http.HttpSession interface. The methods of this interface are useful to do with session management. session The HttpSession object is capable well to track …
HttpSession Example on Visitor Hit Count After learning Session, Session tracking, Session ID and HttpSession and its methods, let us write a program to maintain session tracking using HttpSession interface. The aim of this code is, in a single session, the user visits the site (HitCount servlet) by clicking the submit button number of times. …
Note: You can see the JESSIONID (Session ID) in the output screens at the end. Note: For better understanding, the subject is discussed in Question/Answer format. Note: Before going into this example, it is advised to go through the Cookie API methods and their explanation because these methods are used in this example. 1. What …
Servlet Cookie: Before going into the API, first let us know what for Servlet Cookie is? For better understanding the subject is discussed in Question/Answer format. 1. What is Cookie? For us, Cookie is a class from javax.servlet.http package. But in the open world, a Cookie represents a sweet Biscuit or Chocolate. 2. What a …
The needs of server-side programming are well thought and architectured by Servlet Designers. If a specific Servlet should be started with some default properties well-suited for certain job, the question is where the properties should be assigned. The properties may change seldom and each time the Servlet should be compiled and deployed is also another …
Servlets Tutorial What is Servlet? Servlet is a server-side Java program written as per Servlet API specifications invoked against a client request on the Web using HTTP protocol. Who executes a Servlet? Servlet is executed by a Web server. What is a Web server? Any server connected to Internet is known as Web server. Similarly, …
1. What is MIME? MIME is an abbreviation for "Multipurpose Internet Mail Extensions". At the start, email was intended to transport for textual message only and later added attachments etc. These attachments include different files of various formats like images, text files, video and audio etc. To name these extra attachments MIME was introduced. Browsers …
The developer should specify to the Browser in what style the data is to be sent to the server. The most commonly used styles and available are GET and POST. These styles are to be written in METHOD attribute of <FORM> tag as follows. Let us see their differences and when to use them in …
We have seen earlier, the usage of include(), forward and their 16 differences. Now let us see how to use sendRedirect() method. The sendRedirect(String URL) is defined in javax.servlet.http.HttpServletResponse interface. Let us see what Java API says about sendRedirect() method signature: void sendRedirect(String location) throws IOException: Sends a temporary redirect response to the client using …
Basic Programs Servlets Introduction, Tutorial, Architecture First Servlet Step-by-Step Explanation – Login Screen Validation 7 Steps – Servlets Tomcat Execution Deployment Descriptor – web.xml Sending dynamically filled HTML form to client Sending static HTML form to Client (sendRedirect) Read all Form data at a time – getParameterNames() Example -I Read all HTML Form Fields at …
