I'm happy to announce, we have added Java API support to write GUI tests using LDTP API.
Java LDTP client source:
http://cgit.freedesktop.org/ldtp/ldtp2/tree/ldtp/Ldtp.java
Dependency:
Apache XML-RPC library
Apache codec base 64 library
Tested on both Windows and Linux.
To compile set the CLASSPATH of the following jar files:
commons-codec-1.6.jar
ws-commons-utils-1.0.2.jar
xmlrpc-client-3.1.3.jar
xmlrpc-common-3.1.3.jar
Java documentation available here