难点：aop类是普通的java类，session是无法注入的，那么在有状态的系统中如何获取用户相关信息呢，session是必经之路啊，获取session就变的很重要。思索很久没有办法，后来在网上看到了解决办法。
思路是：
i. SysContext 成员变量 request,session,response
ii. Filter 目的是给 SysContext 中的成员赋值
iii.然后在AOP中使用这个SysContext的值
要用好，需要理解 ThreadLocal和 和Filter 执行顺序
1.aop获取request，response，session等
public class SysContext {
private static ThreadLocal<HttpServletRequest> requestLocal=new ThreadLocal<HttpServletRequest>();
private static ThreadLocal<HttpServletResponse> responseLocal=new ThreadLocal<HttpServletResponse>();
public static HttpServletRequest getRequest(){
return requestLocalget();
}
public static void setRequest(HttpServletRequest request){
requestLocalset(request);
}
public static HttpServletResponse getResponse(){
return responseLocalget();
}
public static void setResponse(HttpServletResponse response){
responseLocalset(response);
}
public static HttpSession getSession(){
return (HttpSession)(getRequest())getSession();
}
}
2.添加过滤器
public class GetContextFilter implements Filter{
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
SysContextsetRequest((HttpServletRequest)request);
SysContextsetResponse((HttpServletResponse)response);
chaindoFilter(request, response);
}
@Override
public void init(FilterConfig config) throws ServletException {
}
}
3.配置web.xml
将这部分放置在最前面，这样可以过滤到所有的请求
<filter> <filter-name>sessionFilter</filter-name> <filter-class>comuneifilterGetContextFilter</filter-class> </filter> <filter-mapping> <filter-name>sessionFilter</filter-name> <url-pattern>*</url-pattern> </filter-mapping>
4.spring aop before
从session中取出用户名，如果不存在，抛出异常跳转，将错误信息放到request中
@Aspect
public class AdminAspect {
ActionContext context = ActionContextgetContext();
HttpServletRequest request;
HttpServletResponse response;
@Before("execution(* comuneiActionAdminActiongetPrivileges())")
public void adminPrivilegeCheck()
throws Throwable {
HttpSession session = SysContextgetSession();
request = SysContextgetRequest();
response = SysContextgetResponse();
String userName = "";
try {
userName = sessiongetAttribute("userName")toString();
if(userName==null||userNameequals(""))
throw new Exception("no privilege");
} catch (Exception ex) {
requestsetAttribute("msg", "{\"res\":\"" + "无权限" + "\"}");
try {
requestgetRequestDispatcher("/jsp/jsonjsp")forward(
request, response);
} catch (ServletException e) {
eprintStackTrace();
} catch (IOException e) {
eprintStackTrace();
}
}
}
}
5.applicationContext.xml
<bean id="adminAspect" class="comuneiaopAdminAspect"></bean>
