There's no sense in reinventing the wheel--here are some servlet support classes I wrote that you can use. Most famous is the file upload package MultipartRequest and MultipartParser. Please read the license before use.

View the Readme
View the License
View the FAQ

View class documentation

Class Index

• class Base64Decoder
• class Base64Encoder
• class CacheHttpServlet
• class DaemonHttpServlet
• class RemoteDaemonHttpServlet (implements java.rmi.Remote)
• class RemoteHttpServlet (implements java.rmi.Remote)
• class HttpMessage
• class HttpsMessage
• class LocaleNegotiator
• class LocaleToCharsetMap
• class MailMessage
• class MultipartRequest
• class MultipartParser
• class FilePart
• class ParamPart
• class FileRenamePolicy
• class DefaultFileRenamePolicy
• class MultipartFilter
• class MultipartWrapper
• class MultipartResponse
• class ParameterParser
• class ServletUtils
• class VersionDetector

• class ParameterNotFoundException

This is a .zip readable by "jar", newer releases are at the top. To be notified when new versions release, subscribe here. Be sure to check out the FAQ and Javadocs below.
Version	Comments
cos-22.05.zip	File upload improvements: Modernized the Javadoc and copyrights Added support for Servlets 2.4 and Java 5. Added an ExceededSizeException type to make catching easier. Added support for EBCDIC machines. Added a workaround for browsers that send Content-Length of -1. Added a workaround for Opera missing parameter names.