Java Practical info : JSP Components And First JSP PageIntroduction to Java Server Pages

JSP Implicit Object's

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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">During the translation phase, the jsp engine declares and
initializes nine commonly used variables in the service method of the generated
servlet. They are implicitly made available to a jsp without need of declaring
them. These are known as implicit variables or implicit objects. They are as
follows.<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Request<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Response<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Session<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Config<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Application<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Page<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Exception<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Out<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">pageContext<o:p></o:p></span></div>
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<b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Request:-</span></b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"> This
object is of type javax.Servlet.http.HttpServletREquest. It refers to the
current request to the jsp. By using this object we can capture the client
data. For example in a scriptlet we can write as follows.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            String
name=request.getParameter(“html textbox name”);<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">%><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">With the above scriptlet we can get the form data directly
into the jsp.<o:p></o:p></span></div>
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<b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Response</span></b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">:- This
objet is of type javax.servlet.http.HttpServletResponse. It  is used for sending customized response to
the client.<o:p></o:p></span></div>
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<b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Session:-</span></b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"> This
object is of type javax.servlet.http.HttpSession. This object is not available
in a jsp if we  say <%@ page session=”false”
%>. In a servlet when we available in a jsp it is imlicitly available. If we
want to implement session tracking in a jsp, we make use of this object.<o:p></o:p></span></div>
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<b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Config:-</span></b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"> The
object is of type javax.servlet.ServletConfig. When initialization parameters
are supplied to the jsp explicitly from the web.xml. we can retrieve them by
using this object.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><% String paramvalue=config.getInitParameter(“Paramname”);
%><o:p></o:p></span></div>
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<b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Application:-</span></b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"> This
is an object of type javax.servlet.ServletContext. It refers to the environment
to which the jsp belongs. Using this object we can retrieve application level
state. All the web components(Jsps & servlets) running in the same
application can share common information. For example if a servlet or another
jsp has stored some info in the ServletContext object, in our current jsp we
can retrieve it as follows.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%  String
value=(String)application.getAttribute(“name”); %><o:p></o:p></span></div>
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<b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Page:-</span></b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"> The is
an object of type java.lang.object. It refers to the instance of the generated
servlet. This is very rarely used in a jsp.<o:p></o:p></span></div>
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<b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Exception:-</span></b><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"> This
object <o:p></o:p></span></div>
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JSP Implicit Object's

During the translation phase, the jsp engine declares and initializes nine commonly used variables in the service method of the gener...

JSP Page Directives

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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">While expressions, scriptlets and declarations are used to
define the logic to be executed at run-time(request processing time),
directives are used to provide pages with information at translation time –
when the jsp page is converted to a servlet.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Directives are used to specify the classes that are
imported, to specify the error page used for catching exceptions, to import tag
libraries and making them available to use on the page etc.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">JSP directives provide general information about the jsp
page to the JSP engine.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">JSP directives do not generate code. They are not part of
the logic within the JSP code. JSP directives provide directions and
instructions to the container, telling it how to handle certain aspects of JSP
specification. </span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">There are 3 types of directives according to jsp specification.<o:p></o:p></span></div>
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<ul style="text-align: left;">
<li><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">            Include
directive</span></li>
<li><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">            Taglib
directive</span></li>
<li><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">            Page
directive</span></li>
</ul>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">A JSP directive is of the form<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%@ directive attribute=value %><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Include Directive:-</b> An include directive telis the JSP
engine to include the contents of another file inline (exactly at the location
of directive usage) in the current jsp. Include file can be another jsp or a
HTML file. Include directive is of the following form </span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%@ include file = “filename”
%><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">The following example include the souce code of the
header.jsp in the current.jsp<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><a href="mailto:%25@include%20file%20=%20%E2%80%9Cheader.jsp%E2%80%9D%25">%@include
file = “header.jsp”%</a><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">When the current jsp(the jsp in which this directive is
used) receives the client request, the jsp enine reads the entire jsp before
translation. Once include directive is encountered, the jsp engine copies the
contents of the header.jsp into the current jsp inline. Then it translates the
current jsp into a servlet. As this happens during the translation phase of the
jsp, we say that directives are translation time instructions that are given to
the jsp container(engine).<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Taglib directive:- This directive is used to tel the
container which tg library a specific JSP requires. It is also used to assign a
prefix gthat is used within the JSP page to identify tags from a specific tag
library. Now jsp engine can locate the code for these tag libraries and get
them ready for use by the JSP page. Taglib directive is of the form</span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"> <%@
taglib prefix=”name” url=”values”%>(More on this in custom tags).<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Page Directive:</b>- This directive informs the engine about the
overall properties of a jsp page. This directive applies to the entire
translation unit and not just to the page in which it is declared. This
directive is of the following form.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><<a href="mailto:%25@page%20attribute=%E2%80%9Dvalue%E2%80%9D%20attribute=%E2%80%9Dvalue%E2%80%9D.....%25">%@page
attribute=”value” attribute=”value”.....%</a>><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Even though there are many attributes for the page
directive, the most frequently used ones are discussed here.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Import:-</b> This attribute is similar to the import statement
in a normal java source code. Once this attribute is used , the jsp container
inserts an import statement into the generated servlet for each of the packages
declared using this attribute. We can import multiple packages in a single tag by
using a comma-separated list of package names. We can also use multiple tags
for readability.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Ex:- <%@ page import=”java.io.*”%><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Session:- </b> This
attribute indicates to the jsp engine whether the current jsp takes part in a
http session. The default value is true. If we don’t want the jsp to
participate ina session, then we have to explicitly say<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%@page session = “false” %><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>errorPage:</b>- we can handle the exceptions in a jsp by writing
try and catch blocks. However, the jsp specification provides cleaner approach.
This approach separates the error hadling code from the main code from the main
page and thus promotes resability of exception handling mechanism. In this
approach, a jsp uses the error page attribute of the page directive to delegate
the exception to another JSP page that has the error handling code.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><<a href="mailto:%25@page%20errorPage=%E2%80%9Dhandler.jsp%E2%80%9D%25">%@page
errorPage=”handler.jsp”%</a>><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>isErrorpage:-</b> This attribute conveys whether the current jsp
can act as an error handler for any other jsp. By default this value is false.
In the abouve example, when we write handler.jsp. In that file we must use the
following statement.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%@page isErrorPage=”true”><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Content Type:-</b> This attribute specifies the MIME type of the
output. The default values is text/html. </span><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">If we want to change the MIME type we can say as follows.</span></div>
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<span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%@page contentType=”image/gif” %><o:p></o:p></span></div>
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JSP Page Directives

While expressions, scriptlets and declarations are used to define the logic to be executed at run-time(request processing time), direct...

JSP Component Expression and Comments

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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">In previous post we are sharing Declaration some of
important point I am coding here also please see my attached video also for
better understanding. <o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">In a declaration we can define (rarely) a static
block and a class also<o:p></o:p></span></div>
<div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">In a Jsp we can have any number of declarations
in any order.<o:p></o:p></span></div>
<div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Variables declared in a declaration are
initialized to java default values.<o:p></o:p></span></div>
<div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Variables in a declaration retain their values
across multiple requests because they are created <o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">And initialized only once.<o:p></o:p></span><br />
<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Expression:-</b> An expression scripting element is an embedded
java expression that is evaluated and converted to a text string. The resulting
text string is placed in a jsp output, in the location at which the element
appears. Expressions act as placeholders for java anguage expressions. An
expression is evaluated each time the page is accessed, and its value is then
embedded in the output HTML. An expression has the following form.<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            <%=any
vaid java expression %><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Examples:</b><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b><br /></b></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%=a+b %><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%=new java.util.Date()%><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
<div class="MsoListParagraphCxSpFirst" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l2 level2 lfo2; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Expressions are inserted into the service method
of the container- generated servlet.<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">We can have any number of expressions per page.<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Embedded java expression should not be
terminated with a semicolon.<o:p></o:p></span></div>
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<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">We can print the value of any object or ay
primitive data type to the output steam using </span><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">an
expression.</span></div>
<div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l2 level2 lfo2; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">We can also use an expression in a jsp action
attribute. In this case the value of the ex-</span><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">Precision
does not go to the output stream. It is evaluated at request time, and its
value is assigned to the attribute. An Expression used in this way is known as
request time attribute expression.</span><br />
<span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;"><br /></span>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Scriptlet:-</b> A scriptlet is used to include complete
fragments of java code in the body of the JSP page. This scripting element
differs from the other two in 2ways.<o:p></o:p></span></div>
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<ul style="text-align: left;">
<li><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">            </span><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">It is not
limited to the declaration of methods and variables.</span></li>
<li><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">            </span><span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;">It does not
generated a string output directly, as expressions do.</span></li>
</ul>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">A scriptlet has the following form <% Any vakud free frin
if hava cide %><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">For example,<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%  int sum=0;<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            For(int
I=1;i<10;i++)<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            Sum+=1;<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">%><o:p></o:p></span></div>
<div class="MsoListParagraphCxSpFirst" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l1 level2 lfo3; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Scriptlet can be placed anywhere within the jsp
body<o:p></o:p></span></div>
<div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l1 level2 lfo3; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">We can place any number of scriptlets in a jsp.<o:p></o:p></span></div>
<div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l1 level2 lfo3; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Each scriptlet is inserted into the service
method of the container – generated servlet in the given order.<o:p></o:p></span></div>
<div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l1 level2 lfo3; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">The scriptlet is executed each time the page is
requested.<o:p></o:p></span></div>
<div class="MsoListParagraphCxSpLast" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l1 level2 lfo3; text-indent: -.25in;">
<span style="font-family: "Courier New"; font-size: 12.0pt; line-height: 115%; mso-fareast-font-family: "Courier New";">o<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">  
</span></span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">As scriptlets contain any java code, they are
typically used for embedding computing logic within a  jsp page.<o:p></o:p></span></div>
<div class="MsoListParagraphCxSpLast" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l1 level2 lfo3; text-indent: -.25in;">
<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Comments in a JSP page</b><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div>
<div class="MsoNormal">
<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">In a jsp we can have 3 kinds of comments<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            Java
comments<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            HTML
comments<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            JSP
comments<o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">In a declaration or a scriplet we can have single line or
multi line java comments. HTML comment is of the form <!—Any commenting text
</span><span style="font-family: Wingdings; font-size: 12.0pt; line-height: 115%; mso-ascii-font-family: Georgia; mso-char-type: symbol; mso-hansi-font-family: Georgia; mso-symbol-font-family: Wingdings;">à</span><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">A JSP comment is of the form <%-- Any commenting text
--%><o:p></o:p></span></div>
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<span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Note:- A JSP comment is also known as a hidden comment as it
is not displayed in the client.<o:p></o:p></span></div>
</div>

JSP Component Expression and Comments

In previous post we are sharing Declaration some of important point I am coding here also please see my attached video also for better un...