MyBatis的mapper.xml文件的参数问题：org.apache.ibatis.builder.IncompleteElementException: Could not find parameter map

配置参数类型有两种选择，即：parameterType和parameterMap

不管参数是否是基本数据类型还是map类型，都是使用parameterType。

parameterMap和resultMap类似，parameterMap通常应用于mapper中有多个参数要传进来时,表示将查询结果集中列值的类型一一映射到java对象属性的类型上，在开发过程中不推荐这种方式。

如果不小心将parameterType写成了parameterMap，如下：

Mapper.java文件

public Long deletePayer(Map<String, Object> paraMap);

Mapper.xml文件

<delete id="deletePayer" parameterMap="map" >
    delete from payer_info where id=#{id}
</delete>

如果Mapper.xml文件没有配置对应parameterMap，这样就会报找不到对应的parameterMap：

org.apache.ibatis.builder.IncompleteElementException: Could not find parameter map com.xxx.yyy.portal.dao.IPayerInfoDao.map
    at org.apache.ibatis.builder.MapperBuilderAssistant.setStatementParameterMap(MapperBuilderAssistant.java:346)
    at org.apache.ibatis.builder.MapperBuilderAssistant.addMappedStatement(MapperBuilderAssistant.java:310)
    at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:109)
    at org.apache.ibatis.session.Configuration.buildAllStatements(Configuration.java:698)
    at org.apache.ibatis.session.Configuration.hasStatement(Configuration.java:668)
    at org.apache.ibatis.session.Configuration.hasStatement(Configuration.java:663)
    at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:175)
    at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:38)
    at org.apache.ibatis.binding.MapperProxy.cachedMapperMethod(MapperProxy.java:49)
    at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:42)
    at com.sun.proxy.$Proxy25.getUserInfoByAccount(Unknown Source)
    at com.xxx.yyy.portal.service.impl.UserInfoServiceImpl.getUserInfoByAccount(UserInfoServiceImpl.java:30)
    at com.xxx.yyy.portal.controller.UserInfoController.ajaxLogin(UserInfoController.java:59)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:781)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:721)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:521)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1096)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:674)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:724)
Caused by: java.lang.IllegalArgumentException: Parameter Maps collection does not contain value for com.xxx.yyy.portal.dao.IPayerInfoDao.map
    at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:791)
    at org.apache.ibatis.session.Configuration.getParameterMap(Configuration.java:570)
    at org.apache.ibatis.builder.MapperBuilderAssistant.setStatementParameterMap(MapperBuilderAssistant.java:344)
    ... 54 more

mapper.xml文件正确的写法：

<delete id="deletePayer" parameterType="map" >
    delete from payer_info where id=#{id}
</delete>

在开发过程中，一定要注意你选择的是parameterType还是parameterMap，如果你发现你选择的是parameterMap，这时你就要小心了，很可能这时项目中一个隐藏的bug，而且还不容易发现，因为报错的信息很模糊，不容易定位到这个问题上来。