A Java implementation of the rsync protocol
yajsync is a port of rsync written in Java.
yajsync currently supports a minimal subset of rsync protocol version 30.0.
Currently implemented rsync options:
Incremental recursion (-r, --recursive)
Preserve owner (-o, --owner)
Preserve group (-g, --group)
Don't map uid/gid values by user/group name (--numeric-ids)
Preserve permissions (-p, --perms)
Preserve times (-t, --times)
Preserve symbolic links (-l, --links)
Transfer directories (-d, --dirs)
Delete extraneous files (--delete)
Don't skip files that match size and time (-I, --ignore-times)
Read daemon-access password from FILE (--password-file=FILE) or environment variable RSYNC_PASSWORD
Module file listings
Archive mode (-a, --archive)
Set I/O read timeout in seconds (--timeout=SECONDS)
Set daemon connection timeout in seconds (--contimeout=SECONDS)
Preserve character device files and block device files (--devices)
Preserve named sockets and named pipes (--specials)
These will currently return an error when trying to actually read device metadata of a device file or trying to create a device file. The reason for this is the inability to handle device files in Java. We still want to support these options in order to be able to support --archive.
yajsync is compliant with at least rsync version 3.0.9.
rsync Java API
Platform independent rsync server
Platform independent rsync client with support for both local and remote file transfers
Native SSL/TLS tunneling
Please be aware though that the API currently is unstable, not documented and will most probably change in the near future.
This software is still unstable and there might be data corruption bugs hiding. So use it only carefully at your own risk.
If you encounter any problems or if you have any questions or just want to provide feedback of any type, then please create a new github issue for this.
Start a Server listening on localhost port 14415, with one implicitly read-only module called Downloads and one readable and writable module called Uploads:
$ cat yajsyncd.conf
This line and all text after a `#' is a comment. Text within square
brackets define the name of a new module. A module definition may be
followed by any number of predefined parameter value statements on
the form key = value. The current available module parameters are:
path An existing path to the module (mandatory).
comment Text that will be shown to the client in module listings
is_readable A boolean (true or false) indicating whether files
may be read below this module (optional, default is
is_writable A boolean (true or false) indicating whether files
may be written below this module (optional, default
fs A Java file system provider (optional).
This is a module definition for a module called Downloads. path is
the only mandatory module parameter. This one also provides a
comment. All modules are implicitly readable but not writable:
[Downloads] path = /path/to/Downloads/ comment = this text will be printed on module listings, it is optional
is_readable = true
is_writable = false
Uploads is both readable and writable; it does not provide a
[Uploads] path = /path/to/Uploads/ is_writable = true
Any non-default Java file system provider may be specified using the
parameter `fs'. Here is an example using the built in Zip file
system provider which provides transparent access to the contents of
a zip-file (see also the client option `--fs'):
[zipfs] fs = jar:file:/path/to/file.zip path = /
Start the server:
$ java -Dumask=$(umask) -jar yajsync-app/target/yajsync-app-0.9.0-SNAPSHOT-full.jar server --port=14415 --config=yajsyncd.conf
Recursively upload the directory called example to Uploads:
java -Dumask=$(umask) -jar yajsync-app/target/yajsync-app-0.9.0-SNAPSHOT-full.jar client --port=14415 -r example localhost::Uploads
The same thing using the alternative syntax:
java -Dumask=$(umask) -jar yajsync-app/target/yajsync-app-0.9.0-SNAPSHOT-full.jar client -r example rsync://localhost:14415/Uploads
And finally the same thing using the original rsync client:
rsync --port=14415 -r example localhost::Uploads
Recursive transfers always implies incremental recursion.
--charsetfor setting common character set (defaults to UTF-8). Note that
--iconvis not supported.
Client local file transfers always uses rsync:s delta transfer algorithm, i.e. it does not have an option
Checksum block size is not computed in the exact same way as rsync. It is computed dynamically based on the file size and is always an even multiple of 2 and at least 512 bytes long.
Wild cards are not supported.
--defer-write- defer writing into a temporary file until the content of the target file needs to be updated.
Support for custom Java file system providers with client option
--fsand server module parameter
git clone https://github.com/perlundq/yajsync.git cd yajsync mvn
Show client/server help (-h argument):
java -jar yajsync-app/target/yajsync-app-0.9.0-SNAPSHOT-full.jar client -h java -jar yajsync-app/target/yajsync-app-0.9.0-SNAPSHOT-full.jar server -h
(Unix/Linux, we must inject necessary umask information as a property, assuming Bourne shell compatible syntax)
java -Dumask=$(umask) -jar yajsync-app/target/yajsync-app-0.9.0-SNAPSHOT-full.jar client -h java -Dumask=$(umask) -jar yajsync-app/target/yajsync-app-0.9.0-SNAPSHOT-full.jar server -h
Recommended extra options to the jvm (i.e. must be placed before the -jar argument):
Turn on assertions:
Use a more memory conservative garbage collector:
Turn on aggressive optimisations:
SSL/TLS is configured externally (see JSSE documentation), but the following properties are used (options to the JVM):
-Djavax.net.ssl.keyStore=... -Djavax.net.ssl.keyStoreAlias=... -Djavax.net.ssl.keyStorePassword=... -Djavax.net.ssl.trustStore=... -Djavax.net.ssl.trustStorePassword=...
javax.net.debug is useful for debugging SSL/TLS. To see available values to javax.net.debug:
Note: client side authorisation is not yet implemented - requires changes to server configuration.
Copyright (C) 1996-2011 by Andrew Tridgell, Wayne Davison, and others
Copyright (C) 2013-2016 Per Lundqvist
yajsync is licensed under GNU General Public License version 3 or later. See the file LICENSE or http://www.gnu.org/licenses/gpl.txt for the license details.