JSP Component Expression and Comments

<div dir="ltr" style="text-align: left;" trbidi="on"> <br /> <div class="MsoNormal"> <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> <div class="MsoNormal"> <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: l0 level2 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><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><!--[endif]--><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;"> <!--[if !supportLists]--><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><!--[endif]--><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;"> <!--[if !supportLists]--><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><!--[endif]--><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;"> <!--[if !supportLists]--><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><!--[endif]--><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> <div class="MsoListParagraphCxSpLast" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><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><!--[endif]--><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> <br /> <div class="separator" style="clear: both; text-align: center;"> <iframe allowfullscreen="allowfullscreen" frameborder="0" height="266" mozallowfullscreen="mozallowfullscreen" src="https://www.youtube.com/embed/IDTm18Hdafc?feature=player_embedded" webkitallowfullscreen="webkitallowfullscreen" width="320"></iframe></div> <div style="text-align: center;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> </div> <div class="MsoListParagraphCxSpLast" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;"> <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%;"><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> <div class="MsoNormal"> <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%;">            <%=any vaid java expression %><o:p></o:p></span></div> <div class="MsoNormal"> <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%;"><b>Examples:</b><o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b><br /></b></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%=a+b %><o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><%=new java.util.Date()%><o:p></o:p></span></div> <div class="MsoNormal"> <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;"> <!--[if !supportLists]--><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><!--[endif]--><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> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l2 level2 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><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><!--[endif]--><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> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l2 level2 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><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><!--[endif]--><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> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l2 level2 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><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><!--[endif]--><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;"> <!--[if !supportLists]--><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><!--[endif]--><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> <br /> <div class="separator" style="clear: both; text-align: center;"> <iframe allowfullscreen="allowfullscreen" frameborder="0" height="266" mozallowfullscreen="mozallowfullscreen" src="https://www.youtube.com/embed/Cg8xWxilihs?feature=player_embedded" webkitallowfullscreen="webkitallowfullscreen" width="320"></iframe></div> <span style="font-family: Georgia, serif; font-size: 12pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal" style="text-indent: .5in;"> <br /></div> <div class="MsoNormal"> <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> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> </div> <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> <br /> <div class="MsoNormal"> <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%;">A scriptlet has the following form <% Any vakud free frin if hava cide %><o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">For example,<o:p></o:p></span></div> <div class="MsoNormal"> <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%;"><%  int sum=0;<o:p></o:p></span></div> <div class="MsoNormal"> <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> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            Sum+=1;<o:p></o:p></span></div> <div class="MsoNormal"> <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;"> <!--[if !supportLists]--><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><!--[endif]--><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;"> <!--[if !supportLists]--><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><!--[endif]--><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;"> <!--[if !supportLists]--><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><!--[endif]--><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;"> <!--[if !supportLists]--><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><!--[endif]--><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;"> <!--[if !supportLists]--><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><!--[endif]--><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> <div class="MsoNormal"> <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> <div class="MsoNormal"> <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> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            Java comments<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            HTML comments<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            JSP comments<o:p></o:p></span></div> <div class="MsoNormal"> <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> <div class="MsoNormal"> <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> <div class="MsoNormal"> <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...

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JSP Components And First JSP Page

<div dir="ltr" style="text-align: left;" trbidi="on"> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="height: 90px; margin-left: auto; margin-right: auto; text-align: center; width: 166px;"><tbody> <tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgy2fDuC40RqB5hx6BeJc-d5H-u4W0eR7t66jdTJQrOfcQk0rzN8Rc2mqNF5YAKZJ_49cgKdJ8d6F1t2ygSLszWXBQZH-IjBKJxpkm05q9ITAZeONGm84AbKZSRDJHsmxMiMG7M-kNdO2c/s1600/jspcomponents.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgy2fDuC40RqB5hx6BeJc-d5H-u4W0eR7t66jdTJQrOfcQk0rzN8Rc2mqNF5YAKZJ_49cgKdJ8d6F1t2ygSLszWXBQZH-IjBKJxpkm05q9ITAZeONGm84AbKZSRDJHsmxMiMG7M-kNdO2c/s1600/jspcomponents.jpg" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;">Image Source Google Images</td></tr> </tbody></table> <div style="text-align: center;"> <br /></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">                               This post describes the components of a jsp page. My last post I try to given introduction about jsp. This post some of the components I am introducing. And I never used any of the components also I created first Hello world JSP page for understanding. Later I can give each component based examples also. Please see simple video end of the post.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">                                A Jsp contains HTML content,jsp tags and java code. By using jsp tags either we can embed java code directly into the jsp page or we can invoke the functionality of java code running behind the scenes. Java code is required for a jsp to provide dynamism to the web page.<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <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%;">Jsp tags can be classified into the following 3 categories.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoListParagraphCxSpFirst" style="margin-left: .75in; mso-add-space: auto; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%; mso-bidi-font-family: Georgia; mso-fareast-font-family: Georgia;">1.<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">       </span></span><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Scripting  Elements<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: .75in; mso-add-space: auto; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%; mso-bidi-font-family: Georgia; mso-fareast-font-family: Georgia;">2.<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">      </span></span><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Directives<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: .75in; mso-add-space: auto; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%; mso-bidi-font-family: Georgia; mso-fareast-font-family: Georgia;">3.<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">      </span></span><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Actions<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: .75in; mso-add-space: auto; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <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%;"><b>Scripting Elements:</b>- The basic functionality of scripting elements is to allow jsp authors to embed java code directly into the jsp. We can classify scripting elements as follows.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoListParagraphCxSpFirst" style="margin-left: .75in; mso-add-space: auto; mso-list: l0 level1 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%; mso-bidi-font-family: Georgia; mso-fareast-font-family: Georgia;">1.<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">       </span></span><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Declaration<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: .75in; mso-add-space: auto; mso-list: l0 level1 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%; mso-bidi-font-family: Georgia; mso-fareast-font-family: Georgia;">2.<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">      </span></span><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Expression<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: .75in; mso-add-space: auto; mso-list: l0 level1 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%; mso-bidi-font-family: Georgia; mso-fareast-font-family: Georgia;">3.<span style="font-family: 'Times New Roman'; font-size: 7pt; line-height: normal;">      </span></span><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Scriptlet<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: .75in; mso-add-space: auto; mso-list: l0 level1 lfo2; text-indent: -.25in;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Declaration:-</b> A Jsp declaration lets us define methods or variables in jsp. These methods and variables become direct members of the container generated servlet class. We can define both instance and static members in a declaration. A declaration has the following form.<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <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%;"><%!<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            //Java Variable declarations and method definitions<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">%><o:p></o:p></span></div> <div class="MsoNormal"> <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%;">For example<o:p></o:p></span></div> <div class="MsoNormal"> <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%;"><%!<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            Private int count=1;//instance variable definition<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            Static int total;//static variable declaration<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            Int getCount()//instance method definition<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            {<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">                        Return count;<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            }<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            Static int getTotal()<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            {<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">                        Return total;<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            }<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">%></span><br /> <br /> <div class="separator" style="clear: both; text-align: center;"> <iframe allowfullscreen="allowfullscreen" frameborder="0" height="266" mozallowfullscreen="mozallowfullscreen" src="https://www.youtube.com/embed/5mDIbYMCIfM?feature=player_embedded" webkitallowfullscreen="webkitallowfullscreen" width="320"></iframe></div> <div style="text-align: center;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Please see for better understanding JSP API click the following link</span></div> <div style="text-align: center;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><a href="http://www.youtube.com/watch?v=PLPzCumtpyw">JSP API</a></span></div> <div style="text-align: center;"> <br /></div> <div style="text-align: center;"> <br /></div> <div style="text-align: center;"> </div> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"></span><br /> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><o:p></o:p></span></div> </div>

JSP Components And First JSP Page

Image Source Google Images                                This post describes the components of a jsp page. My last post I try to gi...

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Life Cycle of a JSP Page

<div dir="ltr" style="text-align: left;" trbidi="on"> <br /> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh20soDeWzp02pq8YarLwZGtcIKNrqd-hZqOur8U3WYOD2b1U7AplXL1v2kNAG6hQwSANlSPJh4s7WgGSxzMebx6tY7jJkQGAWTWknqk_Bmn7DRIZhI-IEY_GtqbOuTzDp8QEoJiEbapjk/s1600/jsplife.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh20soDeWzp02pq8YarLwZGtcIKNrqd-hZqOur8U3WYOD2b1U7AplXL1v2kNAG6hQwSANlSPJh4s7WgGSxzMebx6tY7jJkQGAWTWknqk_Bmn7DRIZhI-IEY_GtqbOuTzDp8QEoJiEbapjk/s1600/jsplife.jpg" /></a></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">                           When a jsp is accessed for the first time, the server is slower in responding. This is because, every jsp page must be converted into an instance of a servlet class before it can be used to service client requests. For each request, the JSP engine checks the time stamps of the source JSP page and the corresponding Servlet class file to determine if the jsp page and the corresponding servlet class file to determine if the jsp page is new or if it has already been converted into class file. Therefore, if we modify a JSP page, the whole process of converting the JSP page into servlet is performed again. The process consists of the following phases known as life cycle phases.<o:p></o:p></span></div> <div class="MsoNormal"> <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: l0 level2 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><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><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Page Translation<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;"> <!--[if !supportLists]--><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><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Page Compilation<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;"> <!--[if !supportLists]--><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><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Generated Servlet class loading<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;"> <!--[if !supportLists]--><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><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Servlet instantiation phase<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;"> <!--[if !supportLists]--><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><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Calling jspInit() known as initialization phase<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;"> <!--[if !supportLists]--><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><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Calling _jspService() known as servicing phase<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><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><!--[endif]--><span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Calling jspDestroy() known as destruction phase<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level2 lfo1; text-indent: -.25in;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Translation phase:</b> During this phase , the jsp engine reads the hsp page, parses it and validates the syntax of the tags, once the validations are completed, the engine creates the java source code that contains public servlet class.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Compilation phase:</b> In this phase, the java compilation unit generated in the previous phases is compiled. The result of this compilation is the class file of the container generated servlet.<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <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%;"><b>Instantiation phase:-</b> The serlvet class is loaded dynamically and the servlet engine creates the servlet instance.<o:p></o:p></span></div> <div class="MsoNormal"> <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%;"><b>Life cycle methods of ajsp:</b> container generated servlet implements  javax.servlet.Servlet interface. jspPage interface declares 2 methods.<o:p></o:p></span></div> <div class="MsoNormal"> <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%;">            JspInit()<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">            JspDestroy()<o:p></o:p></span></div> <div class="MsoNormal"> <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%;">HttpJspPage interface declares one method that serves the Http Client requests.<o:p></o:p></span></div> <div class="MsoNormal"> <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%;">            jspServlice()<o:p></o:p></span></div> <div class="MsoNormal"> <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%;">These methods are known as life cycle methods of a Jsp.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Initialization Phase:</b> The container calls this method to initialize the servlet instance.<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;">Servicing Phase:- In this phase _jspService() method is called by the container every time request  comes to the jsp.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-family: "Georgia","serif"; font-size: 12.0pt; line-height: 115%;"><b>Destruction Phase:-</b> Whe the container is instructed to take the servlet instance out of service, before the instance is sent for garbase collection, container calls the life cycle method jspDestroy().<o:p></o:p></span></div> <div class="MsoNormal"> <br /> <div style="text-align: justify;">      <span style="font-family: Georgia, Times New Roman, serif;">please see for better understanding some people may read or some people may see better understanding that's the reason i am giving every post one video. at least you can see the following video you can understand better way of this post.</span></div> <div style="text-align: justify;"> <span style="font-family: Georgia, Times New Roman, serif;"><br /></span></div> <div style="text-align: justify;"> <span style="font-family: Georgia, Times New Roman, serif;">Please click this link <a href="https://www.youtube.com/watch?v=SIteMzG767M">Life Cycle of JSP page</a></span></div> <div style="text-align: justify;"> <span style="font-family: Georgia, Times New Roman, serif;"><br /></span></div> <div style="text-align: center;"> <span style="font-family: Georgia, Times New Roman, serif;"><br /></span></div> </div> </div>

Life Cycle of a JSP Page

                           When a jsp is accessed for the first time, the server is slower in responding. This is because, every js...

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