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Appendix A

Servlet and JSP Quick Reference

Example Form 

ThreeParamsForm.html

Collecting Three Parameters

  First Parameter:  

  Second Parameter: 

  Third Parameter:  

Filtering HTML Specific Characters

  Must replace 

<

, 

>

, 

"

, 

&

 with 

<

, 

>

, 

"

, and 

&

. Use 

ServletUtilities.filter(htmlString)

 for this substitution. 

See Section 3.6.

A.4 Handling the Client Request: 

HTTP Request Headers

Methods That Read Request Headers

These are all methods in 

HttpServletRequest

.

  public String getHeader(String headerName) 

Returns value of an arbitrary header. Returns 

null

 if header not in 

request.

  public Enumeration getHeaders(String headerName) 

Returns values of all occurrences of header in request. 2.2 only.

  public Enumeration getHeaderNames() 

Returns names of all headers in current request.

  public long getDateHeader(String headerName) 

Reads header that represents a date and converts it to Java date format 

(milliseconds since 1970).

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

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