查询一个实体，返回多个产生的异常

这个bug是我在用spring data JPA 时查询数据库时产生的，由于我是改的同事的代码，我一直以为是查询时返回的optional的原因，后来才发现是数据的问题，返回值是一条数据，而查询出的是两条数据，所以报了这个错误。

2018-10-24 18:25:46.353 [http-nio-13101-exec-3] ERROR o.a.c.c.C.[.[.[.[dispatcherServlet] - Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.IncorrectResultSizeDataAccessException: Query { "$java" : Query: { "version" : "V1.1540374059344" }, Fields: { }, Sort: { } } returned non unique result.] with root cause

org.springframework.dao.IncorrectResultSizeDataAccessException: Query { "$java" : Query: { "version" : "V1.1540374059344" }, Fields: { }, Sort: { } } returned non unique result.

at org.springframework.data.mongodb.core.ExecutableFindOperationSupport$ExecutableFindSupport.oneValue(ExecutableFindOperationSupport.java:145)

at org.springframework.data.mongodb.repository.query.AbstractMongoQuery.lambda$getExecution$4(AbstractMongoQuery.java:124)

at org.springframework.data.mongodb.repository.query.AbstractMongoQuery.execute(AbstractMongoQuery.java:97)

at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:602)

at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:590)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)

at com.sun.proxy.$Proxy148.findByVersion(Unknown Source)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:343)

at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:197)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)

at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)

at com.sun.proxy.$Proxy148.findByVersion(Unknown Source)

at cn.sciencedb.service.impl.ProjectSdoZhCNServiceImpl.collect(ProjectSdoZhCNServiceImpl.java:133)

at cn.sciencedb.controller.ProjectController.collect(ProjectController.java:223)

at cn.sciencedb.controller.ProjectController$$FastClassBySpringCGLIB$$bd1df912.invoke(<generated>)

at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)

at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:746)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)

at org.springframework.aop.framework.adapter.AfterReturningAdviceInterceptor.invoke(AfterReturningAdviceInterceptor.java:55)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:174)

at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:62)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:174)

at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)

at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688)

at cn.sciencedb.controller.ProjectController$$EnhancerBySpringCGLIB$$c64d201d.collect(<generated>)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)

at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)

at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:891)

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797)

at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)

at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)

at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)

at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)

at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)

at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)