Filter的注解配置

<filter >
   <filter-name >authorityFilter</filter-name>
   <filter-class >com.njwbhz.mood.filter.AuthorityFilter</filter-class>
</filter>
<filter-mapping >
   <filter-name >authorityFilter</filter-name>
   <url-pattern >/*</url-pattern>
</filter-mapping>
<filter >
   <filter-name >characterEncodingFilter</filter-name>
   <filter-class >com.njwbhz.mood.filter.CharacterEncodingFilter</filter-class>
   <init-param >
      <param-name >encoding</param-name>
      <param-value >UTF-8</param-value>
   </init-param>
</filter>
<filter-mapping >
   <filter-name >characterEncodingFilter</filter-name>
   <url-pattern >*.do</url-pattern>
</filter-mapping>

package com.njwbhz.mood.filter;
import javax.servlet.*;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet ( value = "*.do", initParams = { @WebInitParam ( name = "encoding", value = "UTF-8" ) } )
public class CharacterEncodingFilter implements Filter {
   //采用配置
   private String encoding;
   @Override
   public void init ( FilterConfig filterConfig ) throws ServletException {
      //初始化的时候获取编码方式
      this.encoding = filterConfig.getInitParameter ( "encoding" );
   }
   @Override
   public void doFilter ( ServletRequest servletRequest , ServletResponse servletResponse , FilterChain filterChain ) throws IOException, ServletException {
      //过滤器的业务逻辑——>有时会说拦截器的业务逻辑
      HttpServletRequest request = ( HttpServletRequest ) servletRequest;
      HttpServletResponse response = ( HttpServletResponse ) servletResponse;
      //获取请求方式
      String method = request.getMethod ( );
      if ( method.equalsIgnoreCase ( "POST" ) ) {
         //设置编码
         request.setCharacterEncoding ( encoding );
      }
      //放行
      filterChain.doFilter ( request , response );
   }
   @Override
   public void destroy ( ) {
   }
}

package com.njwbhz.mood.filter;
import com.njwbhz.mood.entity.User;
import com.njwbhz.mood.util.AuthorityUtil;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
/**
 * 登录验证过滤器
 */
@WebFilter ( "/*" )
public class AuthorityFilter implements Filter {
   private List < String > urls;
   @Override
   public void init ( FilterConfig filterConfig ) throws ServletException {
      //加载文件
      urls = AuthorityUtil.load ( );
   }
   @Override
   public void doFilter ( ServletRequest servletRequest , ServletResponse servletResponse , FilterChain filterChain ) throws IOException, ServletException {
      //每个请求都能被AuthorityFilter拦截住
      //该请求在验证的范围内？
      //先得到当前的URL是什么？
      HttpServletRequest request = ( HttpServletRequest ) servletRequest;
      HttpServletResponse response = ( HttpServletResponse ) servletResponse;
      //如当前的URL：http://127.0.0.1:8080/mood/page/user/login.do?xxxx
      String currentUri = request.getRequestURI ( );// /mood/page/user/login.do?xxxx
      String contextPath = request.getContextPath ( );
      String currentURL = currentUri.substring ( contextPath.length ( ) );// /page/user/login.do?xxxx
      if ( currentURL.contains ( "?" ) ) {
         currentURL = currentURL.substring ( 0 , currentURL.lastIndexOf ( "?" ) );
      }
      //如果在，判断session
      if ( urls.contains ( currentURL ) ) {
         User user = ( User ) request.getSession ( ).getAttribute ( "user" );
         if ( null != user ) { //已经登录过了
            //放行
            filterChain.doFilter ( request , response );
         } else {
            //登录页
            String path = request.getContextPath ( );
            String basePath = request.getScheme ( )
                                + "://" + request.getServerName ( )
                                + ":" + request.getServerPort ( )
                                + path + "/";
            String loginUrl = basePath + "page/user/login.jsp";
            response.setContentType ( "text/html;charset=UTF-8" );
            PrintWriter writer = response.getWriter ( );
            writer.write ( "<script type=\"text/javascript\">" );
            writer.write ( "alert(\"还未登录，请先登录！\");" );
            writer.write ( "window.top.location.href='" );
            writer.write ( loginUrl );
            writer.write ( "';" );
            writer.write ( "</script>" );
            writer.flush ( );
            writer.close ( );
         }
      } else { //如果不在，直接放行
         filterChain.doFilter ( request , response );
      }
   }
   @Override
   public void destroy ( ) {
     
   }
}

删除web.xml中的配置

再测试

问题：

采用XML配置的过滤器链，优先配置的先执行，调整位置即可。

采用@WebFilter注解，如何控制过滤器的执行顺序？

按照类文件的文件名自然排序的顺序