servlet过滤器配置白名单、黑名单

1、web.xml配置

<filter>
        <description>过滤是否登陆</description>
        <filter-name>encodingFilter</filter-name>
        <filter-class>com.stxx.manager.filter.EncodingFilter</filter-class>
        <init-param>
            <description>配置白名单</description>
            <param-name>noCheck</param-name>
            <param-value>
                /login.jsp,
                /register.jsp
            </param-value>
        </init-param>
        <init-param>
            <description>过滤不成功转向地址</description>
            <param-name>redirectPath</param-name>
            <param-value>/login.jsp</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>*.jsp</url-pattern>
    </filter-mapping>

2、创建过滤器

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
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 org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;

/**
 * 登陆过滤 配置白名单、黑名单
 * @author zxf
 *
 */
public class EncodingFilter implements Filter {
    
    Logger log = Logger.getLogger(EncodingFilter.class);
    
    private static final String NO_CHECK = "noCheck";
    private static final String REDIRECT_PATH = "redirectPath";
    private List<String> noCheckList = new ArrayList<String>();
    private String redirectPath = "/login.jsp";

    public void init(FilterConfig init) throws ServletException {
        log.info("初始化filter....");
        String noChecks = init.getInitParameter(NO_CHECK);
        if(StringUtils.isNotBlank(noChecks)){
            if(StringUtils.indexOf(noChecks,",")!=-1){
                for(String no : noChecks.split(",")){
                    noCheckList.add(StringUtils.trimToEmpty(no));
                }
            }else{
                noCheckList.add(noChecks);
            }
        }
        String path = init.getInitParameter(REDIRECT_PATH);
        if(StringUtils.isNotBlank(path)){
            redirectPath = path;
        }
    }
    
    private boolean check(String path) {
        if (noCheckList == null || noCheckList.size() <= 0)
            return false;
        for (String s : noCheckList) {
            if (path.indexOf(s) > -1) {
                return true;
            }
        }
        return false;
    }

    public void doFilter(ServletRequest arg0, ServletResponse arg1,
            FilterChain arg2) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) arg0;
        HttpServletResponse response = (HttpServletResponse) arg1;
        log.info("被filter过滤.......");
        String contextpath = request.getContextPath();
        if("/".equals(contextpath)){contextpath="";}
        if(check(request.getRequestURI())){
            log.info("白名单");
            arg2.doFilter(request, response);
        }else{
            log.info("黑名单");
            response.sendRedirect(response.encodeURL(contextpath+redirectPath));
        }
    }

    public void destroy() {
        log.info("销毁filter....");
    }

}