Filter过滤器例外URL设置

绝地灬酷狼 2022-06-11 06:45 243阅读 0赞

在web.xml声明的一个filter中：

<!– session过滤filter –**>**

<filter>    
    <filter-name>SessionFilter</filter-name>    
    <filter-class>    
    com.iqbon.jcms.web.util.SessionFilter     
    </filter-class>    
    <init-param>    
    <param-name>excludedPages</param-name>    
    <param-value>/admin/login.do</param-value>    
    </init-param>    
    </filter>    
    <filter-mapping>    
    <filter-name>SessionFilter</filter-name>    
    <url-pattern>/admin/*</url-pattern>    
    </filter-mapping>

可以看到url-pattern的设置里面过滤的url规则是/admin/\*，如果要把/admin/login.do排除在过滤url之外。

可以结合init-param的初始化参数和HttpServletRequest的getServletPath()方法来判断。

<init-param>    
    <param-name>excludedPages</param-name>    
    <param-value>/admin/login.do</param-value>    
    </init-param>

其次在filter的 [Java][] 代码中加上判断：

import java.io.IOException;     
      
    import javax.servlet.Filter;     
    import javax.servlet.FilterChain;     
    import javax.servlet.FilterConfig;     
    import javax.servlet.ServletException;     
    import javax.servlet.ServletRequest;     
    import javax.servlet.ServletResponse;     
    import javax.servlet.http.HttpServletRequest;     
    import javax.servlet.http.HttpServletResponse;     
    import javax.servlet.http.HttpSession;     
    import org.apache.commons.lang3.StringUtils;     
    import com.iqbon.jcms.util.KeyConstant;     
        
    /**   
    * session过滤器   
    */    
      
    public class SessionFilter implements Filter {     
      
    /**   
    * 需要排除的页面   
    */    
      
    private String excludedPages;       
    private String[] excludedPageArray;     
      
    /**   
    * @see Filter#destroy()   
    */    
      
    public void destroy() {     
    return;     
    }     
        
    /**   
    * 对session进行判断当前访问是否有登录   
    */    
      
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {     
    boolean isExcludedPage = false;     
    for (String page : excludedPageArray) {//判断是否在过滤url之外     
    if(((HttpServletRequest) request).getServletPath().equals(page)){     
    isExcludedPage = true;     
    break;     
    }     
    }     
      
    if (isExcludedPage) {//在过滤url之外     
    chain.doFilter(request, response);     
    } else {//不在过滤url之外，判断session是否存在     
    HttpSession session = ((HttpServletRequest) request).getSession();     
    if (session == null || session.getAttribute(KeyConstant.SESSION_KEY_USER) == null) {     
    ((HttpServletResponse) response).sendRedirect(“/login.htm”);     
    } else {     
    chain.doFilter(request, response);     
    }     
    }     
    }     
      
    /**   
    * 初始化函数，获取需要排除在外的url   
    */    
      
    public void init(FilterConfig fConfig) throws ServletException {     
    excludedPages = fConfig.getInitParameter(“excludedPages”);     
    if (StringUtils.isNotEmpty(excludedPages)) {     
    excludedPageArray = excludedPages.split(“,”);     
    }     
    return;     
    }     
    }

[Java]: http://lib.csdn.net/base/java