5

I have this code to create a simple .NET .dll. It only returns an int.

But, it is not working inside Java.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ReturnINT
{
    public class ReturnINT
    {

        public static int RetornaInteiro ()
        {
            try
            {
                int number = 2;

                return number;
            }
            catch (Exception)
            {
                return 1;
            }
        }
    }
}

How can I call the method from within Java?

When I Use JNI i have this error IN java:

Exception in thread "main" java.lang.UnsatisfiedLinkError: Dll.RetornaInteiro()V
      at Dll.RetornaInteiro(Native Method)
      at Dll.main(Dll.java:27)
soamazing
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    It's not clear how you'd even *expect* to use a .NET library from Java... were you planning on trying to use JNI? – Jon Skeet May 24 '12 at 19:03
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    Possible duplicate **[Calling C# code from Java?](http://stackoverflow.com/questions/50398/calling-c-sharp-code-from-java)** and **[Call C# dll from a Java Application](http://stackoverflow.com/questions/7992684/call-c-sharp-dll-from-a-java-application)** – Siva Charan May 24 '12 at 19:05
  • @Jon: Does Sun Java interop with COM objects? The Microsoft JVM did. – Ben Voigt May 24 '12 at 19:22
  • @BenVoigt: Not pleasantly, that I'm aware of. – Jon Skeet May 24 '12 at 19:37

2 Answers2

6

Check the http://www.javonet.com as well. With one-jar file you can load this dll and call as follows:

Javonet.AddReference("your-lib.dll");
int result = Javonet.getType("ReturnINT").Invoke("RetornaInteiro");

Javonet will automatically load your library in .NET process and give you access to any classes and types contain within it. Next you can get your type and invoke static method. Method results and arguments are automatically translated between JAVA and .NET types. You can pass for example string or bool arguments like that

Boolean arg1 = true;
String arg2 = "test";
Javonet.getType("ReturnINT").Invoke("MethodWithArguments",arg1,arg2);

And they will be translated automatically.

In addition you can also create instance of your type, subscribe events, set/get properties and fields, handle exceptions or even pass value-type arguments. Check the docs for more details:

http://www.javonet.com/quick-start-guide/

PS: I am member of Javonet team. Therefore feel free to ask me any detailed questions regarding native integrations and our product.

Przemysław Ładyński
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5

You can call it directly: http://jni4net.sourceforge.net/

Or you can call it as an executable.

Jirka Hanika
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  • When I put in java, I has this ERROR: Exception in thread "main" java.lang.UnsatisfiedLinkError: Dll.RetornaInteiro()V at Dll.RetornaInteiro(Native Method) at Dll.main(Dll.java:27) – soamazing May 24 '12 at 19:50
  • @soamazing - https://groups.google.com/group/jni4net/browse_thread/thread/c8877ceb2bb81a57 – Jirka Hanika May 24 '12 at 19:54