Bug 56965 Classpath variable name has to be a valid Java identifier
I20040330 window>preferences>java>classpath variables>new type '444' an error is displayed in the dialog : Invalid name: ''444' is not a valid Java identifier.'. I don't see any reason why the name of the variable has to be a valid Java identifier.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/VariableCreationDialog.java
fPathField.doFillIntoGrid(inner, 3);
		LayoutUtil.setWidthHint(fPathField.getTextControl(null), fieldWidthHint);
		
		DialogField.createEmptySpace(inner, 2);
		fDirButton.doFillIntoGrid(inner, 1);
		
		DialogField focusField= (fElement == null) ? fNameField : fPathField;
		focusField.postSetFocusOnDialogField(parent.getDisplay());
		applyDialogFont(composite);		
		return composite;
	}
		
	
	private class NewVariableAdapter implements IDialogFieldListener, IStringButtonAdapter {
		
		
		public void dialogFieldChanged(DialogField field) {
			doFieldUpdated(field);
		}
		
		
		public void changeControlPressed(DialogField field) {
			doChangeControlPressed(field);
		}
	}
	
	private void doChangeControlPressed(DialogField field) {
		if (field == fPathField) {
			IPath path= chooseExtJarFile();