过滤器之登陆过滤

次过滤器主要用于，判断用户是否登陆，以防直接访问应用中的网页进行提交

Filter 类的写法，

packagefilter;

importjava.io.IOException;

importjavax.servlet.Filter;
importjavax.servlet.FilterChain;
importjavax.servlet.FilterConfig;
importjavax.servlet.ServletException;
importjavax.servlet.ServletRequest;
importjavax.servlet.ServletResponse;
importjavax.servlet.http.*;

importcom.tarena.crm.domain.admin.Manager;

publicclassLoginFilterextendsHttpServletimplementsFilter...{

publicvoiddoFilter(ServletRequestrequest,ServletResponseresponse,FilterChainchain)throwsIOException,ServletException...{
HttpServletRequestreq=(HttpServletRequest)request;
HttpServletResponseres=(HttpServletResponse)response;
if(req.getSession().getAttribute("manager")==null)...{
res.sendRedirect("/crm/core/login.jsp");
}else
chain.doFilter(request,response);
}

publicvoidinit(FilterConfigarg0)throwsServletException...{

}



}

web.xml中的写法：

<url-pattern>/core/adminManage/*</url-pattern>对一个目录进行过滤

或者：

<url-pattern>/core/adminManage/test.jsp</url-pattern>对某一个特定网页进行过滤

<filter>
<filter-name>setlog</filter-name>
<filter-class>filter.LoginFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>setlog</filter-name>
<url-pattern>/core/adminManage/*</url-pattern>
</filter-mapping>