无法保存Spring JPA与数据库的多对多关系:无法通过反射设置字段值:[…]根源为java.lang.NullPointerException [duplicate]

问题描述 投票:0回答:1
我正在尝试在Spring JPA中创建多对多关系的对象并将其保存到数据库。尝试执行ReservationRepository.save(res)时会出现以下错误

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaSystemException: Could not set field value [1] value by reflection : [class com.example.student.entities.ReservationKey.groupId] setter of com.example.student.entities.ReservationKey.groupId; nested exception is org.hibernate.PropertyAccessException: Could not set field value [1] value by reflection : [class com.example.student.entities.ReservationKey.groupId] setter of com.example.student.entities.ReservationKey.groupId] with root cause java.lang.NullPointerException

这里是我要完成的工作的图表:Database diagram

似乎与ReservationKey中的groupId设置器有关。但是,我找不到似乎有问题的地方。我也试图在int和Integer之间切换,这没有帮助。

组实体

@Entity @Table(name = "user_group") public class Group { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "id", unique = true) private Integer id; @Column(name = "name", nullable = false) private String name; @OneToMany(mappedBy = "group") Set<Reservation> reservations; // constructors, getters, setters and stuff

用户实体

@Entity public class User implements UserDetails { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) // same as SQL autoincrement @Column(name = "id", nullable = false) private Integer id; @Column(name = "emailAddress", unique = true, nullable = false) private String emailAddress; @Column(name = "password", nullable = false, length = 60) private String password; @Column(name = "enabled") private boolean accountIsEnabled = true; @OneToMany(mappedBy = "user") Set<Reservation> reservations; // constructors, getters, setters and stuff

预订实体

@Entity public class Reservation { @EmbeddedId ReservationKey reservationKey; @ManyToOne @MapsId("userId") @JoinColumn(name = "user_id") private User user; @ManyToOne @MapsId("groupId") @JoinColumn(name = "group_id") private Group group; @MapsId("myDate") @JoinColumn(name = "my_date") @Temporal(TemporalType.DATE) private Date date; @Column(name = "amount_cooking") private int amountCooking; @Column(name = "amount_eating") private int amountEating; // constructors, getters, setters and stuff

预订复合键

@Embeddable public class ReservationKey implements Serializable { @Column(name = "my_date") @Temporal(TemporalType.DATE) private Date myDate; @Column(name = "group_id") private int groupId; @Column(name = "user_id") private int userId; public ReservationKey() { } public ReservationKey(Date myDate, int groupId, int userId) { this.myDate = myDate; this.groupId = groupId; this.userId = userId; } @Override public boolean equals(Object o) { if (this == o) return true; if (!(o instanceof ReservationKey)) return false; ReservationKey that = (ReservationKey) o; return groupId == that.groupId && userId == that.userId && Objects.equals(myDate, that.myDate); } @Override public int hashCode() { return Objects.hash(myDate, groupId, userId); } public Date getMyDate() { return myDate; } public void setMyDate(Date date) { this.myDate = date; } public int getGroupId() { return groupId; } public void setGroupId(int groupId) { this.groupId = groupId; } public int getUserId() { return userId; } public void setUserId(int userId) { this.userId = userId; } }

完整堆栈跟踪

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaSystemException: Could not set field value [1] value by reflection : [class com.example.student.entities.ReservationKey.groupId] setter of com.example.student.entities.ReservationKey.groupId; nested exception is org.hibernate.PropertyAccessException: Could not set field value [1] value by reflection : [class com.example.student.entities.ReservationKey.groupId] setter of com.example.student.entities.ReservationKey.groupId] with root cause java.lang.NullPointerException: null at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:57) ~[na:na] at java.base/jdk.internal.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:75) ~[na:na] at java.base/java.lang.reflect.Field.set(Field.java:780) ~[na:na] at org.hibernate.property.access.spi.SetterFieldImpl.set(SetterFieldImpl.java:41) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.mapping.Component$ValueGenerationPlan.execute(Component.java:498) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.id.CompositeNestedGeneratedValueGenerator.generate(CompositeNestedGeneratedValueGenerator.java:97) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:115) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:185) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:128) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:55) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:102) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:710) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:696) ~[hibernate-core-5.4.12.Final.jar:5.4.12.Final] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na] at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:366) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE] at com.sun.proxy.$Proxy97.persist(Unknown Source) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na] at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:314) ~[spring-orm-5.2.5.RELEASE.jar:5.2.5.RELEASE] at com.sun.proxy.$Proxy97.persist(Unknown Source) ~[na:na] at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:554) ~[spring-data-jpa-2.2.6.RELEASE.jar:2.2.6.RELEASE] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na] at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:371) ~[spring-data-commons-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:204) ~[spring-data-commons-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:657) ~[spring-data-commons-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:621) ~[spring-data-commons-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:605) ~[spring-data-commons-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:80) ~[spring-data-commons-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:366) ~[spring-tx-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:118) ~[spring-tx-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:178) ~[spring-data-jpa-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE] at com.sun.proxy.$Proxy117.save(Unknown Source) ~[na:na] at com.example.student.controllers.ReservationController.makeReservation(ReservationController.java:67) ~[main/:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na] at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na] at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.FrameworkServlet.doPut(FrameworkServlet.java:920) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:663) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:118) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:158) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:155) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:92) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:92) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:77) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) ~[spring-security-web-5.2.2.RELEASE.jar:5.2.2.RELEASE] at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:358) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:271) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na] at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.33.jar:9.0.33] at java.base/java.lang.Thread.run(Thread.java:830) ~[na:na]

保存新对象

@RestController public class ReservationController { @Autowired UserRepository userRepository; @Autowired GroupRepository groupRepository; @Autowired ReservationRepository reservationRepository; @PutMapping(path = "/reserve", consumes = MediaType.APPLICATION_JSON_VALUE) void makeReservation(@RequestBody String json) { User user = new User("Wouter", new BCryptPasswordEncoder().encode("123"), true); userRepository.save(user); Group group = new Group("Group1"); groupRepository.save(group); userRepository.flush(); groupRepository.flush(); Group g = groupRepository.findByName("Group1").get(); User p = userRepository.findUserById(1); Date date = new Date(System.currentTimeMillis()); Reservation res = new Reservation(p, g, date, 0, 1); reservationRepository.save(res); System.out.println(res); }

java spring jpa many-to-many
1个回答
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投票
关于组类和用户类初始化保留,即

设置保留=新的HashSet <>();

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