Prentice Hall and Sun Microsystems. Personal use only; do not redistribute.

10.3 JSP Scriptlets

241

Figure 10 4 Result of BGColor.jsp when accessed with a bgColor parameter 

having the X11 color value papayawhip.

Using Scriptlets to Make Parts of the JSP File 

Conditional

Another use of scriptlets is to conditionally include standard HTML and JSP

constructs. The key to this approach is the fact that code inside a scriptlet

gets inserted into the resultant servlet's 

_jspService

 method (called by

service

) exactly as written, and any static HTML (template text) before or

after a scriptlet gets converted to 

print

 statements. This means that script 

lets need not contain complete Java statements, and blocks left open can

affect the static HTML or JSP outside of the scriptlets. For example, con 

sider the following JSP fragment containing mixed template text and script 

lets.

<% if (Math.random() < 0.5) { %>

Have a nice day!

<% } else { %>

Have a lousy day!

<% } %>

Second edition of this book: www.coreservlets.com; Sequel: www.moreservlets.com.

Servlet and JSP training courses by book's author: courses.coreservlets.com.