JSP Application object: ▶️ It represents the context within which the JSP is executing. ▶️ It has application scope. ▶️The application object represents the application to which the JSP is executing to which the JSP page belongs. ▶️ It is an instance of the javax.servelt.ServletContext.
JSP Config object: ▶️ config is an implicit object of type ServletConfig. ▶️ This object can be used to get initialization parameter for a particular JSP page. ▶️ The config object is created by the web container for each jsp page.
OS : Windows 10 Jdk : Version 8 IDE : Eclipse Mars Server : Apache Tomcat 7
JSP Application object: ▶️ It represents the context within which the JSP is executing. ▶️ It has application scope. ▶️The application object represents the application to which the JSP is executing to which the JSP page belongs. ▶️ It is an instance of the javax.servelt.ServletContext.
JSP Config object: ▶️ config is an implicit object of type ServletConfig. ▶️ This object can be used to get initialization parameter for a particular JSP page. ▶️ The config object is created by the web container for each jsp page.
OS : Windows 10 Jdk : Version 8 IDE : Eclipse Mars Server : Apache Tomcat 7
jsp:use bean tag is used to declare and used object using tag format in jsp page.
Bean object is declared using use:bean tag in jsp page. set:property tag is used to set the values and get:property tag used to get the values from bean object.
Scope for jsp:bean is set to request so that when a request is transfer to another page its also accessible there.
following is the list of important attributes of jsp:usebean tag ➡ id (name of the object) ➡ name (name of the fully qualified class name of bean) ➡ scope (application,request,session and page), default is page.
In this example bean values are set in process.jsp and then its transferred to welcome.jsp using request dispatcher. Welcome.jsp access the values get the values which were set in process.jsp page.
Summary of files used in this example ➡️ index.jsp (to accept client input) ➡️ process.jsp (to declare and set the values in bean) ➡️ UserBean.java (user bean POJO file) ➡️ welcome.jsp (welcome page to display)
✔️ jsp:useBean standard action tag is use to establish a connection between a jsp page and a java bean. ✔️ In web applications of java, jsp and java bean communication is required in the following two cases: 1️⃣In a real-time MVC project, a model class (business class) will set the data to a java bean and a jsp (view) will read the data from a bean and finally displays it on the browser. 2️⃣If multiple jsp pages need common java logic then it separates that java code into a bean and then we call the bean from jsp.
Video features the following: 👉 How to define Bean class in java 👉 How to use bean class in JSP scriplet 👉 How to use bean using jsp:useBean
It contains the following files 👉 Index.jsp 👉 process.jsp 👉 UserBean.java
Actions tags are used to do things without using Java inside the scriptlets.
They are used to control the flow between pages and to use Java Bean.
They can be used for specific task such as including other resource, forward the request to other resource (html/jsp/servlet), working with java bean objects
Following are the list of files used in example
header.jsp
index.jsp
page1.jsp
page2.jsp
header.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Header</title>
</head>
<body>
<center>
<h1> Ravi R. Oza </h1>
<h4> Home Page </h4>
<hr>
</center>
</body>
</html>
index.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>JSP Action Tag Demo</title>
</head>
<body>
<jsp:include page="header.jsp"></jsp:include>
<form action="page1.jsp">
<h1>JSP Action Tag Demo</h1>
<hr>
<p> Enter your name
<input type="text" name="txtName">
</p>
<p>
<input type="submit" value="Go to Page1">
</p>
</form>
</body>
</html>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Testing Action tags with JSP Param</title>
</head>
<body>
<jsp:include page="header.jsp"></jsp:include>
<h1>Testing Action tags with JSP Param</h1>
<hr>
<p> Name : <%=request.getParameter("txtName") %>
<p> Subject : <%= request.getParameter("txtSub") %>
</body>
</html>
Summary:
Actions tags are used to do things without using Java inside the scriptlets.
They are used to control the flow between pages and to use Java Bean.
They can be used for specific task such as including other resource, forward the request to other resource (html/jsp/servlet), working with java bean objects
OS : Windows 10 Jdk : Version 8 IDE : Eclipse Mars Server : Apache Tomcat 7
<%@ page
language="java"
contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"
errorPage="/myerror.jsp"
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>JSP Page Directives</title>
</head>
<body>
<h1>JSP Page Directives Demo</h1>
<h3>Ravi R. Oza</h3>
<hr/>
<%
String name = null;
int n = name.length();
// or try below
//int n=100/0;
%>
</body>
</html>
myerror.jsp
<%@ page isErrorPage="true" %>
<h1> OOPS, There is an Error</h1>
<h2> Please check the input or wait for server to response.</h2>
<font color="red">
<%= exception %>
</font>
Summary
It is used to provide instructions to a container that connect to current JSP page.
It defines page dependent properties/attributes such as scripting language, error page, etc., which communicates with the Web Container at the time of page translation.
OS : Windows 10 Jdk : Version 8 IDE : Eclipse Mars Server : Apache Tomcat 7
Inclusion of any java/html/jsp resource in jsp file
Following are the list of files used in example
index.jsp
header.html
footer.html
search.jsp
about.jsp
contact.jsp
index.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>JSP Include Tag Example</title>
</head>
<body>
<%@ include file="header.html" %>
<h2>Content of index page is this </h2>
<p> <p> <p> <p> <p> <p> <p> <p>
<%@ include file="footer.html" %>
</body>
</html>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta charset="ISO-8859-1">
<title>search</title>
</head>
<body>
<%@ include file="header.html" %>
<h2> SEARCH </h2>
Search : <input type="text">
<p> <p> <p> <p> <p> <p> <p> <p>
<%@ include file="footer.html" %>
</body>
</html>
about.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta charset="ISO-8859-1">
<title>contact</title>
</head>
<body>
<%@ include file="header.html" %>
<h3>About me </h3>
<h2> Myself Ravi R. Oza </h2>
<h4> Myself Educator, Blogger, YouTuber, Learner </h4>
<p> <p> <p> <p> <p> <p> <p> <p>
<%@ include file="footer.html" %>
</body>
</html>
contact.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta charset="ISO-8859-1">
<title>contact</title>
</head>
<body>
<%@ include file="header.html" %>
<h2>Contact me </h2>
<p> Mail me : Ravi.oza.it@gmail.com
<p> Follow me on Youtube @RaviROza
<p> <p> <p> <p> <p> <p> <p> <p>
<%@ include file="footer.html" %>
</body>
</html>
In this example index page used as home page. Header.jsp contains the header information such as website name, logo & menus. Footer.jsp contains the footer information such as quick links, company’s policies etc., Search.jsp is used to find the information from website. About.jsp is the page which holds the info related to company history & its objective past and future work Contact.jsp is the contact page which is useful when client want to communicate with the company.
Summary: JSP Include Directive is the best way to have reuseability, where a the content of one page or resources can be merged to existing Jsp
OS : Windows 10 Jdk : Version 8 IDE : Eclipse Mars Server : Apache Tomcat 7
If we declare them in declaration tag, both variables, objects & methods, they will be accessible throughout that page. It is used declare public objects or methods for the current page, every scriplet in current page can access it.
OS : Windows 10 Jdk : Version 8 IDE : Eclipse Mars Server : Apache Tomcat 7