/*首先写一个权限过滤filter*/
import javax.servlet.Filter;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.FilterChain;
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;
public class RightFilter
implements Filter {
public void init(FilterConfig filterConfig) throws ServletException {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response;
HttpSession session = req.getSession(true);
//从session里取的用户名信息
String username = (String) session.getAttribute("username");
//判断如果没有取到用户信息,就跳转到登陆页面
if (username == null || "".equals(username)) {
//跳转到登陆页面
res.sendRedirect("http://"+req.getHeader("Host")+"/login.jsp");
}
else {
//已经登陆,继续此次请求
chain.doFilter(request,response);
}
}
public void destroy() {
}
}
下面配置这个过滤器
然后在web.xml里配置那些JSP文件需要登陆权限验证:
1.如果是某个具体的JSP文件(如a.jsp)需要登陆验证
<web-app>
...
<filter>
<filter-name>right</filter-name>
<filter-class>com.taihuatalk.taihua.common.common.RightFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>right</filter-name>
<url-pattern>/a.jsp</url-pattern>
</filter-mapping>
...
</web-app>
2.如果是某一个目录(如a/目录)整个目录下的文件都需要登陆验证:
<web-app>
...
<filter>
<filter-name>right</filter-name>
<filter-class>com.taihuatalk.taihua.common.common.RightFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>right</filter-name>
<url-pattern>/a/*</url-pattern>
</filter-mapping>
...
</web-app>
这是以前论坛一位师兄弄得过滤器的例子.楼主可以参考一下