Basic elements of a JSP page

JSP page elements consist of: static content, directives, expressions, small scripts, declarations, annotations.

JSP directives include:

Page directive: Usually at the top of a JSP page, the same page can have multiple page directives.

Include directive: Embed an external file into the current JSP file and parse the JSP statements in the page.

Taglib directives: Use the tag library to define new custom tags and enable custom behaviors in JSP pages.

Page instruction Syntax:

<% @page Property = "Property Value" Property 2 = "Property value 1, property value 2" ... Property N= "Property value N"%>

Property	Describe	Default value
Language	Develop the scripting language used by JSP pages	Java
Import	Use this property to refer to the class file used in the scripting language	No
ContentType	Used to specify the encoding used by the JSP page	Text/html Iso-8859-1

ContentType is generally set to contenttype= "text/html; Charset=utf-8 "

JSP Notes

Comments on the JSP page. There are several ways:

Comments for HTML: (client visible)

<!--HTML comments--

Comments for JSP: (Client not visible)

<%--HTML Comment--%>

JSP script comments: (can be embedded in the comments of the JSP)

Single-line Comment

/* Multiline Comment */

JSP Script

The Java code that executes in the JSP page.

Grammar:

<% Java Code%>

Example:

<%

Out.println ("moonlit");

%>

JSP Statement

Define variables or methods in the JSP page.

Grammar:

<%! Java Code%>

Example:

<%!

String s = "moonlit"; A string variable was declared

int add (int x, int y) {//declares a function that returns an integral type, which implements the summation of two functions.

return x + y;

}

%>

After declaring the variables and functions, we can use the variables and functions in the next step.

JSP An expression

An expression that executes in a JSP page.

Grammar:

<%= expression%>//Note: The expression does not end with a semicolon

Example: (e.g. display JSP life defined s in JSP page)

<p> Name: <%=s%></p>

Basic elements of a JSP page