DispatcherPortlet.java 文件源码

/**
 * Expose the given action exception to the given response.
 * @param request current portlet request
 * @param response current portlet response
 * @param ex the action exception (may also come from an event phase)
 */
protected void exposeActionException(PortletRequest request, StateAwareResponse response, Exception ex) {
    // Copy all parameters unless overridden in the action handler.
    Enumeration<String> paramNames = request.getParameterNames();
    while (paramNames.hasMoreElements()) {
        String paramName = paramNames.nextElement();
        String[] paramValues = request.getParameterValues(paramName);
        if (paramValues != null && !response.getRenderParameterMap().containsKey(paramName)) {
            response.setRenderParameter(paramName, paramValues);
        }
    }
    response.setRenderParameter(ACTION_EXCEPTION_RENDER_PARAMETER, ex.toString());
    request.getPortletSession().setAttribute(ACTION_EXCEPTION_SESSION_ATTRIBUTE, ex);
}