Terminology

Java Virtual Machine (JVM)

It is a runtime environment that executes a source code written in Java.

JAVA script (JAVA Runnable)

Java class that implements the functionality of application. It is created by application programmer.

WRAPPER

A class ensuring an interface to D2000 System. It is created automatically by D2000 System.

External library

These libraries exist in the form of .jar files or as the group of .class files with a directory structure. They are in binary form and they are placed in application directory %lt;aplikacny_adresar%gt;\java\shared\lib (they can be placed also in subdirectories).
The libraries will be loaded into JVM during initiation of D2000 HI/ D2000 EventHandler and they are still there until D2000 HI/D2000 EVENT is finished, i.e. any changes of libraries on disc during running of JVM will became evident after D2000 HI/D2000 EVENT is restarted.

These libraries cannot use any object of D2000.

User library

These libraries exist in the form of .class files with the directory structure. They are in binary form and they are placed in the application directory %lt;aplikacny_adresar%gt;\java\shared\classes.
They will be loaded into JVM after the picture/event, that uses them, is opened. I.e., if the picture/event is reopened they will be loaded and used again. The libraries can use the objects of structure definition type from D2000 System. But this is not recommended because the reference integrity is not kept in this case. These libraries are compiled against the structure definitions at the time of their compilation and the change of definition structure will cause an inconsistency with results and behaviour that has not been defined.