第一次运行MyBatis时出现错误信息

Question

I have a strange problem when running my application in JBOSS at the first time: The error message is:

javax.servlet.ServletException: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for project.services.dao.workerDAO.getAllWorkers
org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:535)
    org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:433)
    org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
    org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
    org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    org.displaytag.filter.ResponseOverrideFilter.doFilter(ResponseOverrideFilter.java:125)
    org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)

Mapper File: project.services.dao.sql.workerDAO.xml

<?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="project.services.dao.workerDAO">

    <select id="getAllWorkers" parameterType="java.lang.String"
        resultType="Worker">

         Select wrk.Id As workerId, wrk.Nm As workerName
         From Worker wrk

    </select>

</mapper>

However, for the second time, there is no Error Message. Any help will be appreciated. Thanks all.

Answer 1

I had the same trouble, and finally I find the reason is that there are repetitional sql id in mapping xml file.

I hope this is helpful to you.

Answer 2

It seems like a bug in MyBatis. The java class workerDAO can't take the same name as a mapper workerDAO.xml . So, try to change the mapper to workerMapper.xml then test. Please read this article for more information. I hope it's helpful.