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C++ JNI 1_8 - Difficulty executing jar (missing class loads)

gjijutOct 22 2018 — edited Oct 22 2018

I have a jar that I can execute normally using java.exe Trying to execute this jar from a JNI-using C++ project I hit error after error.


WIndows 8

Visual Studio 2017

Netbeans 8.2

JRE/JDK: jdk1.8.0_102

JVM dll path: C:/Program Files/Java/jdk1.8.0_102/jre/bin/server/jvm.dll


In the C project I load the java project as a binary stream, then loop each class entry and use DefineClass( name, null, bytes, size ), five classes fail.

Upon retryng the five, four pass ( so, dependency problem ), one class never passes.

failing class:

import javax.mail.Authenticator;

import javax.mail.PasswordAuthentication;

public class MyAuthenticator extends Authenticator


    String username;

    String password;

    public MyAuthenticator( String u , String p )


        this.username = u;

        this.password = p;



    public PasswordAuthentication getPasswordAuthentication()


        return new PasswordAuthentication( username, password );



If I use FindClass in the C project for Authenticator and PasswordAuthentication, they pass. Java project still get class not found.

If I use class for name in the java project it fails, it passes if I also send the system class loader (default loader is null), but the java project still cant find the class once it gets to the code that calls new.

I also have five custom threads started on the main of the java project, they also complain about class not found (for every thread) eg for Thread1 extends Thread, if I do new Thread1() and it will not be able to. These Thread classes pass the DefineClass loop so they should exist on the jvm.

Im gtting frustrated, but what am I doing wrong? or is JNI too simple to do this?

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Added on Oct 22 2018