loginfilter.java

图书馆管理的源代码文件

package com.nitpro.webmvc.servlet;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class LoginFilter implements Filter {
	public void doFilter(ServletRequest req, ServletResponse resp,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest httpReq = (HttpServletRequest)req;
		HttpServletResponse httpResq = (HttpServletResponse)resp;
		HttpSession session = httpReq.getSession();
		Object obj = session.getAttribute("loginuser");
		if(obj != null){
			chain.doFilter(req, resp);//允许请求通过
		}else{
			httpResq.sendRedirect("/users/login.jsp");//把请求跳转到另一个地方
		}
	}

	public void init(FilterConfig arg0) throws ServletException {
	}
	public void destroy() {
	}

}