5 Ways to Call Java from C# — Honest Comparison from Someone Who Does This Daily

I work at JNBridge, where Java/.NET integration is literally all we do. That means I have a bias — but it also means I've seen every approach to this problem succeed and fail across hundreds of enterprise deployments. I'll be upfront about where our product fits and where it doesn't. Here's an honest breakdown of your options when your C# app needs to talk to Java. The Problem: Two Runtimes, One App C# runs on the .NET CLR, Java runs on the JVM. Completely separate runtime environments with different memory models, type systems, and garbage collectors. They weren't designed to talk to each other. But enterprise software is messy, and mixed stacks are everywhere. Here's how teams actually solve this. Option 1: REST APIs (The Default) Wrap your Java code in a REST service and call it from C#. using var client = new HttpClient (); var response = await client . GetAsync ( "http://localhost:8080/api/calculate" ); var result = await response . Content . ReadFromJsonAsync < CalculationResult