自定义AccessDeniedHandler

在Spring默认的AccessDeniedHandler中只有对页面请求的处理，而没有对Ajax的处理。而在项目开发是Ajax又是我们要常用的技术，所以我们可以通过自定义AccessDeniedHandler来处理Ajax请求。我们在Spring默认的AccessDeniedHandlerImpl上稍作修改就可以了。

public class DefaultAccessDeniedHandler implements AccessDeniedHandler {

    /* (non-Javadoc)
     * @see org.springframework.security.web.access.AccessDeniedHandler#handle(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, org.springframework.security.access.AccessDeniedException)
     */
    private String errorPage;

    //~ Methods ========================================================================================================

    public void handle(HttpServletRequest request, HttpServletResponse response, AccessDeniedException accessDeniedException)
            throws IOException, ServletException {
        boolean isAjax = ControllerTools.isAjaxRequest(request);
        if(isAjax){
            Message msg = MessageManager.exception(accessDeniedException);
            ControllerTools.print(response, msg);
        }else if (!response.isCommitted()) {
            if (errorPage != null) {
                // Put exception into request scope (perhaps of use to a view)
                request.setAttribute(WebAttributes.ACCESS_DENIED_403, accessDeniedException);

                // Set the 403 status code.
                response.setStatus(HttpServletResponse.SC_FORBIDDEN);

                // forward to error page.
                RequestDispatcher dispatcher = request.getRequestDispatcher(errorPage);
                dispatcher.forward(request, response);
            } else {
                response.sendError(HttpServletResponse.SC_FORBIDDEN, accessDeniedException.getMessage());
            }
        }
    }

    /**
     * The error page to use. Must begin with a "/" and is interpreted relative to the current context root.
     *
     * @param errorPage the dispatcher path to display
     *
     * @throws IllegalArgumentException if the argument doesn't comply with the above limitations
     */
    public void setErrorPage(String errorPage) {
        if ((errorPage != null) && !errorPage.startsWith("/")) {
            throw new IllegalArgumentException("errorPage must begin with '/'");
        }

        this.errorPage = errorPage;
    }

}

这里我们直接将异常信息通过PrintWriter输出到前台，然后在前台做统一的处理就可以了。在前台对后台消息统一处理的方法可以参考我的这篇文章http://blog.csdn.net/jaune161/article/details/18135607

最后在配置文件中配置下

<sec:http auto-config="true" access-decision-manager-ref="accessDecisionManager">

    <sec:access-denied-handler ref="accessDeniedHandler"/>

    <sec:session-management invalid-session-url="/login.jsp" />

    <sec:intercept-url pattern="/app.jsp" access="AUTH_LOGIN"/>
    <sec:intercept-url pattern="/**" access="AUTH_GG_FBGBGG"/>

    <sec:form-login login-page="/login.jsp" authentication-failure-url="/login.jsp"
        default-target-url="/index.jsp"/>

</sec:http>

<!-- 自定义权限不足处理程序 -->
<bean id="accessDeniedHandler" class="com.zrhis.system.security.RequestAccessDeniedHandler">
    <property name="errorPage" value="/WEB-INF/error/403.jsp"></property>
</bean>