userloginfilter.java

基于j2ee的电子留言系统

package org.yeeku.web;

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;

import static org.yeeku.util.AppConstants.*;

/**
 * 过滤未登录的非法请求
 */
public class UserLoginFilter implements Filter
{

	private String forwardPath = null;
	private FilterConfig filterConfig = null;

	public void destroy()
	{
		this.forwardPath = null;
		this.filterConfig = null;
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException
	{

		HttpServletRequest httpServletRequest = (HttpServletRequest) request;
		HttpServletResponse httpServletResponse = (HttpServletResponse) response;
		String requesturi = httpServletRequest.getRequestURI();
		// 通过检查session中的变量，过滤请求
		HttpSession session = httpServletRequest.getSession();
		Object currentUser = session.getAttribute(LOGIN_USER);
		// 当前会话用户为空而且不是请求登录，退出登录，欢迎页面和根目录则退回到应用的根目录
		if (currentUser == null
				&& !requesturi.endsWith("/enterRegist.do")
				&& !requesturi.endsWith("/processRegist.do")
				&& !requesturi.endsWith("/processLogin.do")
				&& !requesturi.endsWith("login.jsp")
				&& !requesturi.endsWith("css")
				&& !requesturi.endsWith(httpServletRequest.getContextPath()
						+ "/"))
		{
			System.out.println("Filter启动了作用....");
			httpServletResponse.sendRedirect(httpServletRequest
					.getContextPath()
					+ "/");
			return;
		}
		chain.doFilter(request, response);
	}

	public void init(FilterConfig filterConfig) throws ServletException
	{
		this.filterConfig = filterConfig;
		this.forwardPath = filterConfig.getInitParameter("forwardpath");
	}
}