A servlet container that uses SFTP instead of HTTP as its access protocol.

Overview

The SFTP Servlet Container presents filesystem view of a Java EE web application via the SFTP/SCP protocol.

It behaves in two different ways, depending on if the deployed web application supports the HTTP WebDAV extensions.

Without WebDAV support

If the web application does not support WebDAV extensions (this is typical):

1. Files paths are mapped to Servlet resource URIs.
2. The following table describes how SFTP commands are translated into Servlet requests:

SFTP command	Servlet request method
get	GET
put	PUT
rm	DELETE
rmdir	DELETE

(Commands are based on the OpenSSH SFTP client)

3. Navigating into directories using "cd" always succeeds, even if the directory does not exist, or is inaccessible. E.g., "cd /WEB-INF" succeeds even though you won't be able to access anything under WEB-INF:

sftp> cd /WEB-INF

sftp> get web.xml

Couldn't stat remote file: No such file or directory

File "/WEB-INF/web.xml" not found.

4. All directories appear to be empty except for a WHERE_ARE_MY_FILES.txt.

E.g., If you list the files under root, you only see this file listed even though "/index.jsp" may in fact be a valid Servlet resource:

sftp> ls /

WHERE_ARE_MY_FILES.txt

sftp> get /index.jsp

Fetching /index.jsp to index.jsp

/index.jsp                                   100%  7779    7.6KB/s   00:00

5. You can access resources in a directory using the full path, or by navigating into the directory using "cd" first.

E.g., To access "/foo/bar.gif" you can do:

sftp> get /foo/bar.gif

or:

sftp> cd /foo

sftp> get bar.gif

6. If a path maps to a Servlet resource that is both a file and a directory (this is possible in web applications), you must append a slash (/) to it to navigate to it as a directory. You may access it as a file using the path directly or by appending a slash dot (/.) to it.

E.g., If /baz is both a file and a directory, this is how you would access its file contents:

sftp> get /baz

or:

sftp> get /baz/.

and this is how you would list its directory contents:

sftp> ls /baz/

One special case is the root directory, if it's both a file and directory, this is how you would access its file contents:

sftp> get /.

and this is how you would list its directory contents:

sftp> ls /

7. The following commands are not supported:
   • chgrp
   • chmod
   • chown
   • ln
   • mkdir
   • rename

With WebDAV support

If the web application does support WebDAV extensions, you will be able to access it more or less like a regular filesystem. Specifically in addition to the capabilities above:

1. You will be able to list the contents of directories using ls (this is translated into a WebDAV PROPFIND operation with Depth: 1).
2. You will be able to create directories using mkdir (this is translated into a WebDAV MKCOL operation).
3. However, you will NOT be able to navigate into arbitrary non-existent directories using "cd" (there is no need to).
4. The following commands are not supported:
   • chgrp
   • chmod
   • chown
   • ln
   • rename

Getting Started

Installing SFTP Servlet Container is simply copying JAR files from the distribution package into Tomcat's lib folder, and adding the following lines to the conf/server.xml file:

<Connector port="2222"
           protocol="my.edu.clhs.tomcat.coyote.SftpProtocol"
           anonymousUsername="anonymous"
           sessionTimeout="600000" />

Please refer to INSTALL.txt in the distribution package for more details.