当前位置导航:炫浪网>>网络学院>>编程开发>>JAVA教程>>Java进阶

Web App struts框架里实现Filter


  1 web.xml里添加filter配置信息。
  <filter>
  <filter-name>Authentication</filter-name>
  <filter-class>
  com.nova.colimas.web.filters.AuthenticationFilter
  </filter-class>
  <init-param>
  <param-name>onError</param-name>
  <param-value>/pages/index.jsp</param-value>
  </init-param>
  </filter>
  <filter-mapping>
  <filter-name>Authentication</filter-name>
  <url-pattern>/protect/*</url-pattern>
  </filter-mapping>
  <filter-class>定义使用com.nova.colimas.web.filters.AuthenticationFilter类执行过滤Action。
  <init-param>当验证失败后Forward到/pages/index.jsp
  <filter-mapping>只有当地址包括/protect/时运行filter类
  
  2 实现com.nova.colimas.web.filters.AuthenticationFilter
  package com.nova.colimas.web.filters;
  import java.io.IOException;
  import javax.servlet.RequestDispatcher;
  import javax.servlet.ServletException;
  import javax.servlet.http.*;
  import javax.servlet.Filter;import javax.servlet.FilterChain;
  import javax.servlet.FilterConfig;
  import com.nova.colimas.web.bean.UserBean;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;import org.apache.struts.Globals;
  import org.apache.struts.action.*;
  import com.nova.colimas.web.constants.Constants;
  /**
  * Filter implementation for user authentication。必须实现Filter接口
  * @author tyrone * @version $Id: AuthenticationFilter.java,v 1.0
  */public class AuthenticationFilter implements Filter{
  /**
  * filterConfig will store the reference of FilterConfig
  */  private FilterConfig filterConfig;
  private String onErrorUrl;
  /**
  * store the reference of the FilterConfig.
  * @param config FilterConfig object
  * @throws ServletException
  */  public void init(FilterConfig config) throws ServletException
  {//获得验证失败forward地址
  filterConfig = config;
  onErrorUrl=filterConfig.getInitParameter("onError");
  if (onErrorUrl==null || "".equals(onErrorUrl)){
  onErrorUrl="/pages/index.jsp";
  }
  }
  /**
  * User Authentication is done. If User is authenticated successful then
  * control is transferred to logon URI
  * @param ServletRequest Request
  * @param ServletRequest Response
  * @param FilterChain Filter Chain
  * @throws ServletException,IOException
  */  public void doFilter(ServletRequest request, ServletResponse response, FilterChain next)
  throws IOException, ServletException
  {
  HttpServletRequest httpRequest = (HttpServletRequest)request;
  HttpServletResponse httpResponse=(HttpServletResponse)response;
  // Current session
  HttpSession httpSession = httpRequest.getSession();
  //Session里是否有用户信息。
  if (httpSession.getAttribute(Constants.USER_KEY) == null)
  {
  ActionErrors errors=new ActionErrors();
  errors.add(ActionErrors.GLOBAL_ERROR,
  new ActionError("error authentication"));
  httpRequest.setAttribute(Globals.ERROR_KEY,errors);
  //没有,验证失败forward到/pages/index.jsp
  httpRequest.getRequestDispatcher(onErrorUrl).forward(httpRequest,httpResponse);
  }else//成果过滤Action结束
  next.doFilter(request,response);
  }
  /**
  * destroy() method is called by the servlet container
  */  public void destroy()
  {
  }
  }
相关内容
赞助商链接