### Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'Messageresult'. ?Cause: java.lang.ClassNotFoundException: Cannot find class: Messageresult at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:26) at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:54) at org.apache.ibatis.session.SqlSessionFactoryBuilder.build(SqlSessionFactoryBuilder.java:38) at com.gjh.db.DbAcess.getSqlSession(DbAcess.java:19) at com.gjh.dao.MessageDao.queryMessageList(MessageDao.java:21) at com.gjh.service.ListService.queryMessageList(ListService.java:11) at com.gjh.servlet.ListServlet.doGet(ListServlet.java:31) at com.gjh.servlet.ListServlet.doPost(ListServlet.java:39) at javax.servlet.http.HttpServlet.service(HttpServlet.java:646) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE mapper? ? PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"? ? "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="Message">? <resultMap type="com.gjh.bean.Message" id="Messageresult">? ? <id column="id" jdbcType="INTEGER" property="id"/>? ? <result column="command" jdbcType="VARCHAR" property="command"/>? ? <result column="description" jdbcType="VARCHAR" property="description"/>? ? <result column="content" jdbcType="VARCHAR" property="content"/>? </resultMap>? ? <select id="queryMessage" parameterType="com.gjh.bean.Message" resultType="Messageresult" >? ? SELECT ?id, ?command, description, content FROM message? <where>? ? <if test="command != null and !&quot;&quot;.equals(command.trim())"> ? ? and command=#{command} ? ?</if> ? ?<if test="description != null and !&quot;&quot;.equals(description.trim())"> ? ? and description like '%' #{description} '%' ? ?</if>? ? </where>? </select></mapper>