RightFilter.class
package edu.qdgxy.util;
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;
import edu.qdgxy.model.Admin;
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
Admin admin = (Admin) session.getAttribute("admin");
// 判断如果没有取到用户信息,就跳转到登陆页面
if (admin == null) {
// 跳转到登陆页面
res.sendRedirect("http://" + req.getHeader("Host") + "SalaryMS/admin_login.jsp");
} else {
// 已经登陆,继续此次请求
chain.doFilter(request, response);
}
}
public void destroy() {
}
}
然后再web.xml中配置该过滤器
<filter>
<filter-name>right</filter-name>
<filter-class>edu.qdgxy.util.RightFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>right</filter-name>
<!-- 要过滤的文件夹 -->
<url-pattern>/pages/back/*</url-pattern>
</filter-mapping>