# A fatal error has been detected by the Java Runtime Environment: C#->C++/CLI Wrapper->Java

See more:

C++/CLI

C#

Java

JNI

So this is the error I get on Eclipse:

#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (0xe0434352), pid=7696, tid=8632
#
# JRE version: Java(TM) SE Runtime Environment (8.0_45-b15) (build 1.8.0_45-b15)
# Java VM: Java HotSpot(TM) Client VM (25.45-b02 mixed mode, sharing windows-x86 )
# Problematic frame:
# C [KERNELBASE.dll+0xc42d]
#
# Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
This is the C# dll:

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

namespace StringAPI
{
    public class Test
    {
        public string Something(string username)
        {
            return username;
        }
    }
}

This is the Java code:

import java.util.Scanner;

public class String_Displayer
{
    static
    {
        System.loadLibrary("StringAPIWrapper");
    }

    public native String something(String username);

    public static void main(String[] args)
    {
        String_Displayer sd = new String_Displayer();
        System.out.println("Please enter your name:");
        @SuppressWarnings("resource")
        Scanner scan = new Scanner(System.in);
        String username = scan.next();
        String s = sd.something(username);
        System.out.print(sd.something(username));
    }

And this is the C++/CLI Wrapper dll:

#include "stdafx.h"
#include "com_StringDisplayer_String_Displayer.h"
#include "StringAPIWrapper.h"
#include <vcclr.h>
#include <iostream>

using namespace std;
using namespace System;
using namespace StringAPI;

JNIEXPORT jstring JNICALL Java_com_StringDisplayer_String_1Displayer_something (JNIEnv *env, jclass jc, jstring js)
{
    const jchar* temp = (env)->GetStringChars(js, 0); 
    if (temp == NULL)
    {
        return NULL;
    }

    String^ managedString = gcnew System::String((const wchar_t*)temp);
    env->ReleaseStringChars(js, temp);
    Test^ test1 = gcnew Test();
    String^ result = test1->Something(managedString);

    pin_ptr<const wchar_t> resultChars = PtrToStringChars(result);
    return env->NewString((jchar*)resultChars, result->Length);
}

What I'm sure of is the function that calls the C# function is working properly. I've also tried to just write it directly from C++/CLI using System::Console::Writeline without converting to a jstring but it didn't work. I know that using Writeline does actually work: If I do System::Console::WriteLine("test"); and comment out the call to C#, "test" is written to the java console.