* This action displays error pages when unhandled exceptions occur
 * during search operations or page navigation.
 */
public class ErrorAction extends FessSearchAction {

    /**
     * Default constructor for ErrorAction.
     */
    public ErrorAction() {
        super();
    }

    // ===================================================================================

            return redirect(ErrorAction.class);
        }
        final String url = DocumentUtil.getValue(doc, fessConfig.getIndexFieldUrl(), String.class);
        if (url == null) {
            saveError(messages -> messages.addErrorsDocumentNotFound(GLOBAL, form.docId));
            return redirect(ErrorAction.class);
        }

        if (fessConfig.isSearchLog()) {

            return redirect(ErrorAction.class);
        }

        final String content = viewHelper.createCacheContent(doc, form.hq);
        if (content == null) {
            saveError(messages -> messages.addErrorsDocidNotFound(GLOBAL, form.docId));
            return redirect(ErrorAction.class);
        }

        final StreamResponse response =