We present the Prolog Cafe system that translates Prolog into Java via the WAM. Prolog Cafe provides multi-threaded Prolog engines. A Prolog Cafe thread seem to be conceptually an independent Prolog evaluator and communicates with each other through shared Java objects. Prolog Cafe also has the advantages of portability, extensibility, smooth interoperation with Java, and modularity. In performance, our translator generates faster code for a set of classical Prolog benchmarks than an existing Prolog-to-Java translator jProlog.