Go语言视频零基础入门到精通

javalearner

一、 使浏览器不缓存页面的过滤器 import javax.Servlet.*;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException; /**
  * 用于的使 Browser 不缓存页面的过滤器
  */
public class ForceNoCacheFilter implements Filter {  public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException
  {
   ((HttpServletResponse) response).setHeader("Cache-Control","no-cache");
   ((HttpServletResponse) response).setHeader("Pragma","no-cache");
   ((HttpServletResponse) response).setDateHeader ("Expires", -1);
   filterChain.doFilter(request, response);
  }  public void destroy()
  {
  }     public void init(FilterConfig filterConfig) throws ServletException
  {
  }
} 二、检测用户是否登陆的过滤器 import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.List;
import java.util.ArrayList;
import java.util.StringTokenizer;
import java.io.IOException; /**
  * 用于检测用户是否登陆的过滤器，如果未登录，则重定向到指的登录页面<p>
  * 配置参数<p>
  * checkSessionKey 需检查的在 Session 中保存的关键字<br/>
  * redirectURL 如果用户未登录，则重定向到指定的页面，URL不包括 ContextPath<br/>
  * notCheckURLList 不做检查的URL列表，以分号分开，并且 URL 中不包括 ContextPath<br/>
  */
public class CheckLoginFilter
  implements Filter
{
     protected FilterConfig filterConfig = null;
     private String redirectURL = null;
     private List notCheckURLList = new ArrayList();
     private String sessionKey = null;  public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException
  {
   HttpServletRequest request = (HttpServletRequest) servletRequest;
   HttpServletResponse response = (HttpServletResponse) servletResponse;    HttpSession session = request.getSession();
   if(sessionKey == null)
   {
    filterChain.doFilter(request, response);
    return;
   }
   if((!checkRequestURIIntNotFilterList(request)) && session.getAttribute(sessionKey) == null)
   {
    response.sendRedirect(request.getContextPath() + redirectURL);
    return;
   }
   filterChain.doFilter(servletRequest, servletResponse);
  }  public void destroy()
  {
   notCheckURLList.clear();
  }  private boolean checkRequestURIIntNotFilterList(HttpServletRequest request)
  {
   String uri = request.getServletPath() + (request.getPathInfo() == null ? "" : request.getPathInfo());
   return notCheckURLList.contains(uri);
  }  public void init(FilterConfig filterConfig) throws ServletException
  {
   this.filterConfig = filterConfig;
   redirectURL = filterConfig.getInitParameter("redirectURL");
   sessionKey = filterConfig.getInitParameter("checkSessionKey");   String notCheckURLListStr = filterConfig.getInitParameter("notCheckURLList");   if(notCheckURLListStr != null)
   {
    StringTokenizer st = new StringTokenizer(notCheckURLListStr, ";");
    notCheckURLList.clear();
    while(st.hasMoreTokens())
    {
     notCheckURLList.add(st.nextToken());
    }
   }
  }
} 三、字符编码的过滤器 import javax.servlet.*;
import java.io.IOException; /**
  * 用于设置 HTTP 请求字符编码的过滤器，通过过滤器参数encoding指明使用何种字符编码,用于处理HTML Form请求参数的中文问题
  */
public class CharacterEncodingFilter
  implements Filter
{
  protected FilterConfig filterConfig = null;
  protected String encoding = "";  public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException
  {
         if(encoding != null)
          servletRequest.setCharacterEncoding(encoding);
         filterChain.doFilter(servletRequest, servletResponse);
  }  public void destroy()
  {
   filterConfig = null;
   encoding = null;
  }     public void init(FilterConfig filterConfig) throws ServletException
  {
          this.filterConfig = filterConfig;
         this.encoding = filterConfig.getInitParameter("encoding");  }
} 四、资源保护过滤器

1. 
   
2. package catalog.view.util;
   
3. import javax.servlet.Filter;
   
4. import javax.servlet.FilterConfig;
   
5. import javax.servlet.ServletRequest;
   
6. import javax.servlet.ServletResponse;
   
7. import javax.servlet.FilterChain;
   
8. import javax.servlet.ServletException;
   
9. import javax.servlet.http.HttpServletRequest;
   
10. import java.io.IOException;
    
11. import java.util.Iterator;
    
12. import java.util.Set;
    
13. import java.util.HashSet;
    
14. //
    
15. import org.apache.commons.logging.Log;
    
16. import org.apache.commons.logging.LogFactory;
    
17. /**
    
18. * This Filter class handle the security of the application.
    
19. *

复制代码

* It should be configured inside the web.xml. * * @author Derek Y. Shen */ public class SecurityFilter implements Filter { //the login page uri private static final String LOGIN_PAGE_URI = "login.jsf"; //the logger object private Log logger = LogFactory.getLog(this.getClass()); //a set of restricted resources private Set restrictedResources; /** * Initializes the Filter. */ public void init(FilterConfig filterConfig) throws ServletException { this.restrictedResources = new HashSet(); this.restrictedResources.add("/createProduct.jsf"); this.restrictedResources.add("/editProduct.jsf"); this.restrictedResources.add("/productList.jsf"); } /** * Standard doFilter object. */ public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { this.logger.debug("doFilter"); String contextPath = ((HttpServletRequest)req).getContextPath(); String requestUri = ((HttpServletRequest)req).getRequestURI(); this.logger.debug("contextPath = " + contextPath); this.logger.debug("requestUri = " + requestUri); if (this.contains(requestUri, contextPath) && !this.authorize((HttpServletRequest)req)) { this.logger.debug("authorization failed"); ((HttpServletRequest)req).getRequestDispatcher(LOGIN_PAGE_URI).forward(req, res); } else { this.logger.debug("authorization succeeded"); chain.doFilter(req, res); } } public void destroy() {} private boolean contains(String value, String contextPath) { Iterator ite = this.restrictedResources.iterator(); while (ite.hasNext()) { String restrictedResource = (String)ite.next(); if ((contextPath + restrictedResource).equalsIgnoreCase(value)) { return true; } } return false; } private boolean authorize(HttpServletRequest req) { //处理用户登录 /* UserBean user = (UserBean)req.getSession().getAttribute(BeanNames.USER_BEAN); if (user != null && user.getLoggedIn()) { //user logged in return true; } else { return false; }*/ } }