JSP6 (JSP instruction and JSP action Element)

A. JSP directives are used to set the entire JSP page related properties

Directives can have many properties, which exist as key-value pairs and are separated by commas.

Three types of directive tags in JSPs:

page directive

The page directive provides the container with instructions for using the current page. A JSP page can contain multiple page directives.

Syntax format for page directives:

<%@ page attribute= "value"%>

Properties

The following table lists the properties that are related to page directives:

For example:

<%@ Page Language="Java"Import="java.util.*"pageencoding="UTF-8"ErrorPage="showerror.jsp"%><%@ Page Language="Java"Import="java.util.*"pageencoding="UTF-8"Iserrorpage="true"%>

Settings for buffers

 <%@ Page Language="Java"pageencoding="gb2312"AutoFlush="true"Buffer="8kb" %>

include Directives

JSPs can include other files through the include directive. The included file can be a JSP file, an HTML file, or a text file. The contained file is as if it were part of the JSP file and will be compiled at the same time.

<% @ include file = " file relative URL address " %>

two. JSP action Elements

JSP actions can dynamically insert files, reuse JavaBean components, redirect users to additional pages, and so on.

<attribute= "value"/>

Several commonly used are as follows:

< Jsp:include ></ Jsp:include > <  page= "include1.jsp"></jsp:include> tag Dynamic loading, can be with parameters or without parameters

Pass Value:

<page= "include2.jsp"><Jsp:param    Name= "username"  value= "PKD"/></JSP: Include>

Value:

<%      out.println (request.getparameter ("username"));     %>

<jsp:forward></jsp:forward>

<page= "index.jsp"></jsp:forward> tags jump directly to a page, with parameters, or without parameters

Pass Value:

<%   int Age= About; %>      <Jsp:forwardpage= "forword1.jsp">    <Jsp:paramvalue= "<%=age%>"name= "Age"/>    <Jsp:paramname= "User"value= "PKD"/>    </Jsp:forward>

Value:

<%=Request.getparameter (" Age") %><BR/>    <%=Request.getparameter ("User") %>

JSP in Javabean Use

Define assignment:

<Jsp:usebeanID= "Students"class= "PCTC." Studentsbean ">   <Jsp:setpropertyname= "Students" Property= "FirstName"/>   <Jsp:setpropertyname= "Students" Property= "LastName"/>   <Jsp:setpropertyname= "Students" Property= "Age"/>   </Jsp:usebean>

Attribute value:

<name= "Students"  Property= "FirstName"/>  <name= "Students"  Property= "LastName"/> <  name= ' Students '  Property= ' age '/>

Method:

<% =  %>

Job: Show the records in the database in the page, according to the age of the teacher 30 and salary >3000, with the javabean tag to achieve

JSP6 (JSP instruction and JSP action Element)