springboot+springdatajpa：javax.persistence.EntityExistsException运行异常

1. 控制台异常输出

org.springframework.dao.DataIntegrityViolationException: A different object with the same identifier value was already associated with the session : [com.leaderment.demo.pojo.Product#0]; nested exception is javax.persistence.EntityExistsException: A different object with the same identifier value was already associated with the session : [com.leaderment.demo.pojo.Product#0]
	at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:393)
	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:225)
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:527)
	at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:61)
	at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:242)
	at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:153)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
	at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
	at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
	at com.sun.proxy.$Proxy84.save(Unknown Source)
	at com.leaderment.demo.service.impl.ProductServiceImpl.saveCountryModelUser(ProductServiceImpl.java:73)
	at com.leaderment.demo.handler.ProductHandler.countryModelUser(ProductHandler.java:17)
	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)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)
Caused by: javax.persistence.EntityExistsException: A different object with the same identifier value was already associated with the session : [com.leaderment.demo.pojo.Product#0]
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:118)
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:157)
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:164)
	at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:790)
	at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:768)
	at sun.reflect.GeneratedMethodAccessor48.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:350)
	at com.sun.proxy.$Proxy78.persist(Unknown Source)
	at sun.reflect.GeneratedMethodAccessor48.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:305)
	at com.sun.proxy.$Proxy78.persist(Unknown Source)
	at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:490)
	at sun.reflect.GeneratedMethodAccessor107.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:377)
	at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:200)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:641)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:605)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$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.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
	at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
	... 65 more

• 解决方式

  1. 重点在这行异常输出：

     Caused by: javax.persistence.EntityExistsException: A different object with the same identifier value was already associated with the session
     

     可以看出来是JPA实体类出现异常

  2. 原因：JPA生成的实体，主键不会自动添加自增策略

      @Id
         @Column(name = "user_id")
         //@GeneratedValue(strategy = GenerationType.IDENTITY) 主键没有添加自增策略
         public int getUserId() {
             return userId;
         }
     

  3. 解决：将上 2 实体类的主键添加自增策略，完整实体类如下

     @Entity
     public class User {
         private int userId;
         private String userName;
         private String userPassword;
         private Integer roleId;
         private Integer departmentId;
         private Integer businessUnitId;
         private Timestamp ctime;
         private String remark;
         private String userDisplayName;
     
         @Id
         @Column(name = "user_id")
         @GeneratedValue(strategy = GenerationType.IDENTITY)
         public int getUserId() {
             return userId;
         }
     
         public void setUserId(int userId) {
             this.userId = userId;
         }
     
         @Basic
         @Column(name = "user_name")
         public String getUserName() {
             return userName;
         }
     
         public void setUserName(String userName) {
             this.userName = userName;
         }
     
         @Basic
         @Column(name = "user_password")
         public String getUserPassword() {
             return userPassword;
         }
     
         public void setUserPassword(String userPassword) {
             this.userPassword = userPassword;
         }
     
         @Basic
         @Column(name = "role_id")
         public Integer getRoleId() {
             return roleId;
         }
     
         public void setRoleId(Integer roleId) {
             this.roleId = roleId;
         }
     
         @Basic
         @Column(name = "department_id")
         public Integer getDepartmentId() {
             return departmentId;
         }
     
         public void setDepartmentId(Integer departmentId) {
             this.departmentId = departmentId;
         }
     
         @Basic
         @Column(name = "business_unit_id")
         public Integer getBusinessUnitId() {
             return businessUnitId;
         }
     
         public void setBusinessUnitId(Integer businessUnitId) {
             this.businessUnitId = businessUnitId;
         }
     
         @Basic
         @Column(name = "ctime")
         public Timestamp getCtime() {
             return ctime;
         }
     
         public void setCtime(Timestamp ctime) {
             this.ctime = ctime;
         }
     
         @Basic
         @Column(name = "remark")
         public String getRemark() {
             return remark;
         }
     
         public void setRemark(String remark) {
             this.remark = remark;
         }
     
         @Basic
         @Column(name = "user_display_name")
         public String getUserDisplayName() {
             return userDisplayName;
         }
     
         public void setUserDisplayName(String userDisplayName) {
             this.userDisplayName = userDisplayName;
         }
     
         @Override
         public boolean equals(Object o) {
             if (this == o) return true;
             if (o == null || getClass() != o.getClass()) return false;
             User user = (User) o;
             return userId == user.userId &&
                     Objects.equals(userName, user.userName) &&
                     Objects.equals(userPassword, user.userPassword) &&
                     Objects.equals(roleId, user.roleId) &&
                     Objects.equals(departmentId, user.departmentId) &&
                     Objects.equals(businessUnitId, user.businessUnitId) &&
                     Objects.equals(ctime, user.ctime) &&
                     Objects.equals(remark, user.remark) &&
                     Objects.equals(userDisplayName, user.userDisplayName);
         }
     
         @Override
         public int hashCode() {
             return Objects.hash(userId, userName, userPassword, roleId, departmentId, businessUnitId, ctime, remark, userDisplayName);
         }
     }