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Chapter

SP has three main capabilities for including external pieces into a JSP

document. 

J

The 

include

 directive lets you reuse navigation bars, tables, and other

elements in multiple pages. The included elements can contain JSP

code and thus are inserted into the page before the page is translated into a

servlet. This capability is discussed in Section 12.1.

Although including external pieces that use JSP is a powerful capability,

other times you would rather sacrifice some power for the convenience of

being able to change the included documents without updating the main JSP

page. For example, my family's church has a Web page on which it posts snow

cancellation announcements. This page is updated by 6:30 AM on Sundays

when there is a cancellation. It is hardly reasonable to expect the Web devel 

oper to post this update; he probably sleeps in and barely makes the late late

service. Instead, a simple plain text file could be uploaded with the

announcement, and the main page could use the 

jsp:include

 element to

insert the announcement into the home page. This capability is discussed in

Section 12.2.

Although this book is primarily about server side Java, client side Java in

the form of Web embedded applets continues to play a role, especially within

fast corporate intranets. The 

jsp:plugin

 element is used to insert applets

that use the Java Plug In into JSP pages. This capability is discussed in Sec 

tion 12.3.

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