Books from amazon:
 
 

JLog

JLog is an implementation of a Prolog interpreter, written in Java. It’s primary benefit is that can be run on almost any platform supporting Java (such as a web browser), and as such it is well suited for educational purposes. It works as both an application and as an applet.

PROLOG+CG

PROLOG+CG is a logic programming language that integrates PROLOG, Conceptual Graph, Object-oriented programming and JAVA

JESS

JESS is a clone of the popular CLIPS expert system shell written entirely in Java. With Jess, you can conveniently give your applets the ability to ‘reason’.

javalog

Prolog in java (javalog) ver 0.02. To avoid paradox, javalog uses concept of world. You can make paradox in prolog. and extension, you can make truth server. The world of internet will be a single prolog interpreter. For data exchange, I used S expression. You can exchange also Lisp server.

jProlog

jProlog is close to Clocksin-Mellish Prolog, with lots of the typical builtins.You need a Prolog system (SICStus, BinProlog, BIMprolog are ok – SWI doesn’t work apparently)