The Vensim DLL is a native file and comes with an interface for Java. To us this you will need to include in the calling Java class at the top:
import com.vensim.Vensim;
and then when it is instantiated a line in the form
private Vensim vensim = new Vensim("vendll32") ;
where "vendll32" is the full DLL. You would use "vdpdll32" for the double precision DLL. Because the Vensim class is contained in a .jar file you will need to specify this when compiling and running your Java application. For example using the command line interface you would enter:
javac –cp vensim.jar; MyApplication.java
java –cp vensim.jar; MyApplication
to compile and run your application.
There is a simple Java example in the java subdirectory of the dll directory. When you complete your application you will need to package it into a jar file, and it is easiest to include the contents of the vensim.jar file in that file.