ClickHandlers can only be added to Anchors in GWT, and not AnchorElements. The solution however is to wrap the AnchorElement in an Anchor and add the ClickHandler to the Anchor:
Anchor excelAnchor = Anchor.wrap(excelAnchorElement); excelAnchor.addClickHandler(new ClickHandler() { @Override public void onClick(ClickEvent event) { //DO SOMETHING HERE } });