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....");
	}

}