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290

Chapter 13 Using JavaBeans with JSP

double quotes, and noncontainer elements should end the tag with 

/>

, not 

just 

>

.

There are also a few character sequences that require special handling in

order to appear inside attribute values:

To get 

'

 within an attribute value, use 

\'

.

To get 

"

 within an attribute value, use 

\"

.

To get 

\

 within an attribute value, use 

\\

.

To get 

%>

 within an attribute value, use 

%\>

.

To get 

<%

 within an attribute value, use 

<\%

.

Accessing Bean Properties

Once you have a bean, you can access its properties with 

jsp:getProperty

,

which takes a 

name

 attribute that should match the 

id

 given in 

jsp:useBean

and a 

property

 attribute that names the property of interest. Alternatively,

you could use a JSP expression and explicitly call a method on the object that

has the variable name specified with the 

id

 attribute. For example, assuming

that the 

Book

 class has a 

String

 property called 

title

 and that you've cre 

ated an instance called 

book1

 by using the 

jsp:useBean

 example just given,

you could insert the value of the 

title

 property into the JSP page in either

of the following two ways:

<%= book1.getTitle() %>

The first approach is preferable in this case, since the syntax is more acces 

sible to Web page designers who are not familiar with the Java programming

language. However, direct access to the variable is useful when you are using

loops, conditional statements, and methods not represented as properties.

If you are not familiar with the concept of bean properties, the standard

interpretation of the statement  this bean has a property of type 

T

 called 

foo

is  this class has a method called 

getFoo

 that returns something of type 

T

 and

has another method called 

setFoo

 that takes a 

T

 as an argument and stores it

for later access by 

getFoo

.  

Setting Bean Properties: Simple Case

To modify bean properties, you normally use 

jsp:setProperty

. This action

has several different forms, but with the simplest form you just supply three

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