loginfilter.java

以前做的一个j2ee的项目

package gov.gdlt.ssgly.taxweb.comm;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

/**
 * A filter used for resource protection. *
 *
 * <p>Title: LoginFilter</p>
 * <p>Description: 税收管理员系统</p>
 * <p>Copyright: Copyright (c) 2005 广州市地方税务局</p>
 * <p>Company: 信息中心</p>
 * @author Lemon
 * @version 1.0
 * @since 2005.8.10.
 */

public class LoginFilter extends HttpServlet implements Filter {
    private FilterConfig filterConfig;
    //Handle the passed-in FilterConfig
    public void init(FilterConfig filterConfig) throws ServletException {
        this.filterConfig = filterConfig;
    }

    //Process the request/response pair
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain filterChain) {
        try {
            HttpServletRequest httpRequest = (HttpServletRequest) request;
            HttpSession session = httpRequest.getSession();
            String url = httpRequest.getRequestURI();

            if (session.getAttribute("loginPassed") == null &&
                url.indexOf("login") < 0 && url.indexOf("welcome") < 0) {
                HttpServletResponse httpResponse = (HttpServletResponse)
                        response;
                httpResponse.sendRedirect("/ssgly/login.jsf");
            } else {
                filterChain.doFilter(request, response);
            }
        } catch (ServletException sx) {
            filterConfig.getServletContext().log(sx.getMessage());
        } catch (IOException iox) {
            filterConfig.getServletContext().log(iox.getMessage());
        }
    }

    //Clean up resources
    public void destroy() {
    }
}