NetBeans API: Create and open a temporary in-memory file with explicit non-serialized semantic data.

opentempfile.java

FileSystem fileSystem = FileUtil.createMemoryFileSystem();
// Store the actual text that will be displayed to the memory file system
FileObject tempFileObject = FileUtil.copyFile(FileUtil.toFileObject(inputFile), fileSystem.getRoot(), inputFile.getName(), "linterp");
DataObject od = DataObject.find(tempFileObject);

EditorCookie ec = od.getLookup().lookup(EditorCookie.class);
Document opened = ec.openDocument();
if (opened != null) {
    // here I add the additional data as a property to the Document without needing to serialize it
    opened.putProperty(LexerDebuggerEditorKit.PROP_INTERP_DATA, lexerInterpreterData);
    final OpenCookie oc = od.getLookup().lookup(OpenCookie.class);
    if (oc != null) {
        if (SwingUtilities.isEventDispatchThread()) {
            oc.open();
        } else {
            SwingUtilities.invokeLater(new Runnable() {
                @Override
                public void run() {
                    oc.open();
                }
            });
        }
    }
}