Problem

Can I connect to a broker from a Java Client

Solution

Yes you can.. Please refer to "The webMethods Broker Administration Java API Programmer's Guide" that describes the application programming interfaces (API) that you use to create event-based applications, using the Java language, which perform administrative functions.

This document is intended for use by programmers who are developing event--based
applications using webMethods Broker.

See also How to use the Broker Java API to Publish Documents