File Uploads in Java
Using HTTP
On the server
If you are using
Servlets 3.0 or later, see the Servlet Specification for information on uploading files.
Servlet 2.x and
JSP do not make any special provisions for multipart requests (file uploads), so when using Servlet 2.x and JSP, developers either have to depend on third party libraries or make their own framework.
Fabricating your own framework is incredibly difficult (multi-part requests are not trivial to parse) and would be re-inventing the wheel. Fortunately, there are several very good open source frameworks out there; with clear instructions and code examples.
The two most popular are Jakarta
Commons FileUpload and
com.oreilly.servlet
Note that request.getParameter() and its related methods do not work with multi-part requests, and will always return null when dealing with multipart form data.
On the client
If you want to upload files in conjunction with
Commons HttpClient,
this
introductory article tells how to use FileUpload in conjunction with the
Commons HttpClient package.
Using FTP
It is possible to do basic FTP operations using J2SE:
To obtain a directory listing, simply create the URL with the directory you wish to index.
The Jakarta
Commons Net package includes an FTP client which supports the full range of FTP commands.
Using SMB
The Samba project has a
Java client library that can access Windows shares and Samba servers. Its API mimics the
java.io.File class, and is thus easy to use if you are familiar with File.
Using WebDAV
Tomcat ships with a
WebDAV server component. The client side could be one of numerous available
libraries, or the file managers of Mac OS X or Windows.
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