谁见过下面的异常？(ps:百度上有说是返回类型错了，也有说是传递参数的个数不对，可是我看都不是啊，报错说应该返回一条结果或是空的，结果却有15条记录，那该怎么处理呢)
0
悬赏园豆：5
[已关闭问题]
关闭于 2017-07-26 12:38
org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.TooManyResultsException: Expected one result (or null) to be returned by selectOne(), but found: 15 at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:364) at com.sun.proxy.$Proxy12.selectOne(Unknown Source) at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:159) at com.xhw.dao.DaoSupport.findForObject(DaoSupport.java:110) at com.xhw.service.data.kwords.impl.KwordsService.findById(KwordsService.java:70) at com.xhw.service.data.kwords.impl.KwordsService$$FastClassBySpringCGLIB$$e67f5b02.invoke(<generated>) at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:708) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644) at com.xhw.service.data.kwords.impl.KwordsService$$EnhancerBySpringCGLIB$$2ae2a9ed.findById(<generated>) at com.xhw.controller.data.kwords.KwordsController.validateKwords(KwordsController.java:257) 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:749) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863) at javax.servlet.http.HttpServlet.service(HttpServlet.java:646) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) 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.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61) at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108) at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137) at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66) at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449) at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365) at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90) at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83) at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383) at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362) at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344) at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) 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: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:503) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2466) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2455) 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:745) Caused by: org.apache.ibatis.exceptions.TooManyResultsException: Expected one result (or null) to be returned by selectOne(), but found: 15 at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:66) at sun.reflect.GeneratedMethodAccessor70.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:354) ... 76 more
接口中代码 public Boolean hasThisKwordId(String KwordId)throws Exception; public String findLastKwordId(String parentid)throws Exception; Controller中代码 @RequestMapping(value="/validate") @ResponseBody public Object validateKwords() throws Exception { PageData pd = new PageData(); Map<String,Object> map = new HashMap<String,Object>(); pd = this.getPageData(); if (kwordsService.findById(pd)!=null) { map.put("msg", "true"); }else{ map.put("msg", "false"); } return AppUtil.returnObject(pd, map); } @RequestMapping(value="/findkwordid") @ResponseBody public Object findKwordId() throws Exception{ PageData pd = new PageData(); Map<String,Object> map = new HashMap<String,Object>(); pd = this.getPageData(); String nextKwordid=getNextKwordId(pd.getString("parentid")); map.put("nextKwordid", nextKwordid); return AppUtil.returnObject(pd, map); } private String getNextKwordId(String parentid) throws Exception { String lastKwordId=kwordsService.findLastKwordId(parentid); String nextKwordId=""; if (StringUtil.isNullOrEmpty(lastKwordId)) { nextKwordId=CodeConst.KWORDS_KWORDID_ROOT.equals(parentid) ?CodeConst.KWORDS_KWORDID_START :parentid+CodeConst.KWORDS_KWORDID_START; }else { if (lastKwordId.length()>CodeConst.KWORDS_KWORDID_INTERVAL) { nextKwordId=parentid+StringUtil.haoAddOne(lastKwordId.substring(lastKwordId.length()-CodeConst.KWORDS_KWORDID_INTERVAL,lastKwordId.length()),CodeConst.KWORDS_KWORDID_FORMAT); }else { nextKwordId=StringUtil.haoAddOne(lastKwordId, CodeConst.KWORDS_KWORDID_FORMAT); } } return nextKwordId; } Mapper中代码 <select id="hasThisKwordId" parameterType="String" resultType="int"> select count(0) from <include refid="tableName"></include> where KWORDID = #{KWORDID} </select> <select id="findLastKwordId" parameterType="String" resultType="String"> select KWORDID from <include refid="tableName"></include> where PARENTID=#{PARENTID} order by KWORDID desc limit 0,1 </select> jsp中代码 function validateKwordId(str){ var parentid=$("#PARENTID").val() var result=false $.ajax({ url:'kwords/validate', data:{PARENTID:parentid,KWORDID:str}, async:false, dataType:'json', type:'post', success:function(resp){ if(resp.msg=='true'){ result=true } } }); return result; } function validateKwordName(str){ var parentid=$("#PARENTID").val() var result=false $.ajax({ url:'kwords/validate', data:{PARENTID:parentid,KWORDNAME:str}, async:false, dataType:'json', type:'post', success:function(resp){ if(resp.msg=='true'){ result=true } } }); return result; } function changeParentid(){ var pid=$("#PARENTID").val() $.ajax( { type : "POST", url : "kwords/findkwordid", data : "parentid=" + pid, success : function(data) { $("#KWORDID").val(data.nextKwordId); if(validateKwordName($("#KWORDNAME").val())){ $("#KWORDNAME").tips({ side:3, msg:'主题名称重复，请更换', bg:'#AE81FF', time:2 }); $("#KWORDNAME").focus(); } }, error : function() { $("#KWORDID").tips({ side:3, msg:'主题代码变更失败', bg:'#AE81FF', time:2 }); $("#KWORDID").focus(); } }); }
所有回答(2)
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接口写的是什么？返回类型应该是集合，但是你写的是对象
public Boolean hasThisKwordId(String KwordId)throws Exception; public String findLastKwordId(String parentid)throws Exception;
可是，不管什么返回类型都是集合吗？
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这个错误是你定义的方法只能返回一个entity，即一条数据，而你返回了一个list，即多条数据。若想返回多条定义的时候应该用List。 String只能返回一个字符串而不是list，或许你可以用行转列把多条转为一条，才会返回String
怎么转？
@JAVA~~~:这个就是 ，（）里填写你所查的字段， select wm_concat(t.dummy) from dual t；
查出来的就是一行。这是最简单的用wm_concat 函数，不过这个函数最多能存4000，超过四千会报错。太长的话得自己写个函数吧。
