Java Interop Case Studies

The goal of interop is not to show off syntax—it is to build clean, testable integrations.

In real systems, the best interop code tends to look like this:

• a small namespace that wraps a Java library
• plain data in and plain data out
• resource management handled explicitly (connections, streams, threads)
• unit tests targeting your wrapper API, not the Java library itself

This section applies those ideas to concrete examples so you can recognize good boundaries in production code.

In this section

• Adding Clojure to a Java Application
  Add Clojure to an existing Java application through a narrow integration point, choosing functionality that benefits from data transformation, concurrency, or REPL-driven iteration.
• Wrapping Java Libraries in Clojure
  Wrap a Java library behind a Clojure namespace so callers work with plain data, focused functions, explicit resources, and translated exceptions instead of library-specific objects everywhere.
• Building Hybrid Systems with Java and Clojure
  Design JVM systems where Java and Clojure coexist intentionally, with clear ownership boundaries, measured performance trade-offs, and stable contracts between the two languages.