JSF中Filter的实现
大概思路是 建一个filter 过滤除登陆页面的其他所有页面 在filter 里取到session 判断里面是否有值 如果有 则正常跳转 否则跳转到登陆页或你需要的指定页面即可~代码如下:
在web.xml里面加上filter :
<!-- 用户登录过滤器开始 -->
<filter>
<filter-name>checkLoginFilter </filter-name>
<filter-class>CheckLoginFilter </filter-class>
<init-param>
<param-name>checkSessionKey </param-name>
<param-value>LoginUser </param-value>
</init-param>
<init-param>
<param-name>redirectURL </param-name>
<param-value>/login.jsf </param-value>
</init-param>
<init-param>
<param-name>notCheckURLList </param-name>
<param-value>/login.jsf </param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>checkLoginFilter </filter-name>
<url-pattern>*.jsf </url-pattern>
</filter-mapping>
<!-- 用户登录过滤器结束 -->
<filter>
<filter-name>checkLoginFilter </filter-name>
<filter-class>CheckLoginFilter </filter-class>
<init-param>
<param-name>checkSessionKey </param-name>
<param-value>LoginUser </param-value>
</init-param>
<init-param>
<param-name>redirectURL </param-name>
<param-value>/login.jsf </param-value>
</init-param>
<init-param>
<param-name>notCheckURLList </param-name>
<param-value>/login.jsf </param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>checkLoginFilter </filter-name>
<url-pattern>*.jsf </url-pattern>
</filter-mapping>
<!-- 用户登录过滤器结束 -->
CheckLoginFilter.java
/**
* 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 <String> notCheckURLList = new ArrayList <String>();
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();
response.setHeader("Cache-Control","no-cache");
response.setHeader("Pragma","no-cache");
response.setDateHeader ("Expires", -1);
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());
}
}
}
}
* 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 <String> notCheckURLList = new ArrayList <String>();
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();
response.setHeader("Cache-Control","no-cache");
response.setHeader("Pragma","no-cache");
response.setDateHeader ("Expires", -1);
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());
}
}
}
}
(转载)