JavaServer Pages, Second Edition

Reading Bean Properties

A bean’s data is represented by its properties. The CartoonBean used in Example 6-1 has only one property, named fileName, but other beans may have many different properties. The fileName property’s value is the name of an image file that contains a cartoon. There are two ways to insert a bean property value in a JSP page. Let’s look at them one at a time.

Using the <jsp:getProperty> Action

Once you have created a bean and given it a name using the <jsp:useBean> action, you can get the bean’s property values with another JSP standard action, named <jsp:getProperty>. This action obtains the current value of a bean property and inserts it directly into the response body.

To include the current fileName property value in the page, simply use this tag:

<jsp:getProperty name="cartoon" property="fileName" />

The name attribute, set to cartoon, refers to the specific bean instance declared by the <jsp:useBean> action. The <jsp:getProperty> action locates this bean and asks it for the value of the property specified by the property attribute. In Example 6-1, the property value is used as the src attribute value for an HTML <img> element. The result is the page shown in Figure 6-1. The way this bean is implemented, the fileName property value changes every time you access the property; when you reload the page, a different cartoon strip is shown.

Figure 6-1. A JSP ...