jni4net

bridge between Java and .NET (intraprocess, fast, object oriented, open-source)

How to use

Download binary package.
study samples inside of the binary package, read samples\ReadMe.md play along.
- Try samples\helloWorldFromCLR there is ReadMe.md inside.
- Try samples\helloWorldFromJVM there is ReadMe.md inside.
How calling from Java to .NET works
How calling from .NET to Java works
Troubleshooter
Email group

How it works

Using reflection we grab public method signatures for core classes of .NET and Java and generated proxy classes for the other side.
We have .NET version of JNI API.
We use JNI to forward the call from .NET proxies to methods on real Java objects. (explanation)
We use JNI to register .NET implementation of native methods of Java proxies to forward call to methods on real .NET objects. (explanation)

Features

Intraprocess - it means that both VMs are in same process. Any call uses same thread and same stack for both environments. It's relatively fast.
Proxies - we use proxies which look like and behave like the real/original object. Marshaled by reference except for primitive types and arrays.
Garbage collected - if you don't create cycle between VMs heaps, the proxies and instances are collected and released properly.
Proxygen - tool to wrap your own library. Works with reflection, so you need just .jar or .dll, and proxygen config file. You could wrap most CLR or JVM classes.
Core - core classes of JDK and .NET framework are already included in jni4net. Using that for reflection and invocation across the boundary is possible.
Samples - are included with the binaries. See ReadMe.md in directories
Troubleshooting - use knowledge base or Stackoverflow or ask people
Platforms - at the moment only Windows 32 and 64 bits. CLR 2.0 and CLR 4.0. JRE 1.5 and above.
License - opensource, GPL tools and MIT runtime
Status - Runtime is currently stable with ocasional bug fix. The proxygen is ugly, but I don't have enough time to rewrite it. I tried in branch 0.9
Contact - use mailing group or talk to pavel.savara@gmail.com

.NET/C# to Java Hello World -> Full sample

using net.sf.jni4net;
public class Program
{
    private static void Main()
    {
        Bridge.CreateJVM(new BridgeSetup());
        java.lang.System.@out.println("Greetings from C# to Java world!");
    }
}

Java to .NET Hello World -> Full sample

import net.sf.jni4net.Bridge;
import java.io.IOException;
import java.lang.String;

public class Program {
    public static void main(String[] args) throws IOException {
        Bridge.init();
        system.Console.WriteLine("Greetings from Java to .NET world!");
    }
}