import javax.servlet.*;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
?
/**
?* 用于的使 Browser 不緩存頁面的過濾器
?*/
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
?{
?}
}
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;
/**
?* 用于檢測用戶是否登陸的過濾器，如果未登錄，則重定向到指的登錄頁面<p>
?* 配置參數<p>
?* checkSessionKey 需檢查的在 Session 中保存的關鍵字<br/>
?* redirectURL 如果用戶未登錄，則重定向到指定的頁面，URL不包括 ContextPath<br/>
?* notCheckURLList 不做檢查的URL列表，以分號分開，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());
?? }
? }
?}
}
import javax.servlet.*;
import java.io.IOException;
/**
?* 用于設置 HTTP 請求字符編碼的過濾器，通過過濾器參數encoding指明使用何種字符編碼,用于處理Html Form請求參數的中文問題
?*/
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");
?}
}