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

A.10 JSP Scripting Elements

533

Encoding URLs

In case servlet is using URL rewriting to implement session tracking, you

should give the system a chance to encode the URLs.

  Regular URLs 

String originalURL = someRelativeOrAbsoluteURL;

String encodedURL = response.encodeURL(originalURL);

out.println("...");

  Redirect URLs 

String originalURL = someURL; // Relative URL OK in 2.2

String encodedURL = response.encodeRedirectURL(originalURL);

response.sendRedirect(encodedURL);

A.10 JSP Scripting Elements

Types of Scripting Elements

  Expressions: <%= expression %> 

Evaluated and inserted into servlet's output. You can also use

expression

  Scriptlets: <% code %> 

Inserted into servlet s 

_jspService

 method (called by 

service

). You 

can also use

code

  Declarations: <%! code %> 

Inserted into body of servlet class, outside of any existing methods. You 

can also use

code

Template Text

  Use 

<\%

 to get 

<%

 in output.

<%   JSP Comment   %>

  All other non JSP specific text passed through to output page.

Predefined Variables

Implicit objects automatically available in expressions and scriptlets (not dec 

larations).

  request: the 

HttpServletRequest

 associated with request.

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

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