There are two possible ways to bridge PHP and Java: you can either integrate PHP into a Java Servlet environment, which is the more stable and efficient solution, or integrate Java support into PHP. The former is provided by a SAPI module that interfaces with the Servlet server, the latter by this Java extension.
The Java extension provides a simple and effective means for creating and invoking methods on Java objects from PHP. The JVM is created using JNI, and everything runs in-process.
This extension is EXPERIMENTAL. The behaviour of this extension—including the names of its functions and any other documentation surrounding this extension—may change without notice in a future release of PHP. This extension should be used at your own risk.