Bug 39906 Add Constructurs from field: Should not show static fields
20030711 Static fields are usually not initialized in constructors
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/CreateNewConstructorAction.java
else if (firstElement instanceof ICompilationUnit)	{			
				IType type= ((ICompilationUnit) firstElement).findPrimaryType();
				if (type.isInterface()) {
					MessageDialog.openInformation(getShell(), fDialogTitle, ActionMessages.getString("CreateNewConstructorAction.interface_not_applicable")); 					
					return;
				}
				else 
					run((IType)EditorUtility.getWorkingCopy(((ICompilationUnit) firstElement).findPrimaryType()), new IField[0], editor, false);
			}
		} catch (CoreException e) {
			ExceptionHandler.handle(e, getShell(), fDialogTitle, ActionMessages.getString("CreateNewConstructorAction.error.actionfailed")); 
		}	
	}
	private IType getSelectedType(IStructuredSelection selection) throws JavaModelException {
		Object[] elements= selection.toArray();
		if (elements.length == 1 && (elements[0] instanceof IType)) {
			IType type= (IType) elements[0];
			if (type.getCompilationUnit() != null && type.isClass()) {
				return type;
			}
		}
		else if (elements[0] instanceof ICompilationUnit) {
			ICompilationUnit cu= (ICompilationUnit) elements[0];
			IType type= cu.findPrimaryType();
			if (!type.isInterface())
				return type;
		}
		return null;
	}