如何在JPA REST中设置外键

我有以下JPA实体

my JPA entity :: BookForUser 
@Id
private int id;

@ManyToOne
@JoinColumn(name="e_mail")
private User user;// I do not want User object in the table, 
//I want a string e_mail to be foreign key in my entity table

var booking = { e_mail: localStorage.getItem("email"),...

上面是我的JSON代码，用于填充JS中的bookForUser对象 . 我正在使用JAVA REST作为后端 . 但在成功路由REST调用后，我收到异常

SEVERE：Servlet [com.RRS.config.RRSConfig]的Servlet.service（）在路径[/ RRS_2]的上下文中引发异常org.glassfish.jersey.server.ContainerException：com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException ：无法识别的字段“e_mail”在[来源：org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream@178546ce; line：1，column：12]（通过引用链：com.RRS.bean.Reservation [“e_mail”]）]与根本原因com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException：无法识别的字段“e_mail”（类clasName ），未在[来源：org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream@178546ce;中标记为可忽略;行：1，柱：12]在com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from（UnrecognizedPropertyException.java:51）在com.fasterxml.jackson.databind.DeserializationContext.reportUnknownProperty（DeserializationContext.java:839）在玉米.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty（StdDeserializer.java:1045）在com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty（BeanDeserializerBase.java:1352）在com.fasterxml.jackson.databind .deser.BeanDeserializerBase.handleUnknownVanilla（BeanDeserializerBase.java:1330）位于com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize（BeanDeserializer.java:264）的com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize（BeanDeserializer） .java：125）com.fasterxml.jackson.databind.ObjectReader._bind（ObjectReader.java:1470）位于com.fasterxml.jackson的com.fasterxml.jackson.databind.ObjectReader.readValue（ObjectReader.java:912） . jaxrs.base.ProviderBase.readFrom（临viderBase.java:811）org.glassfish.jersey.message.internal.ReaderInterceptorExecutor $ TerminalReaderInterceptor.invokeReadFrom（ReaderInterceptorExecutor.java:256）org.glassfish.jersey.message.internal.ReaderInterceptorExecutor $ TerminalReaderInterceptor.aroundReadFrom（ReaderInterceptorExecutor.java： 235）在org.glassfish.jersey.message.internal.ReaderInterceptorExecutor.proceed（ReaderInterceptorExecutor.java:155）在org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundReadFrom（MappableExceptionWrapperInterceptor.java:74）在org.glassfish.jersey .message.internal.ReaderInterceptorExecutor.proceed（ReaderInterceptorExecutor.java:155）在org.glassfish.jersey.message.internal.MessageBodyFactory.readFrom（MessageBodyFactory.java:1085）在org.glassfish.jersey.message.internal.InboundMessageContext.readEntity （InboundMessageContext.java:874）位于org.glassfish.jersey.server.internal.inj的org.glassfish.jersey.server.ContainerRequest.readEntity（ContainerRequest.java:271）位于org.glassfish.jersey.server.spi.internal的org.glassfish.jersey.server.spi.internal.ParamValueFactoryWithSource.provide（ParamValueFactoryWithSource.java:71）的ect.EntityParamValueFactoryProvider $ EntityValueFactory.provide（EntityParamValueFactoryProvider.java:96） . org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider $ AbstractRethource.MerodMisodMisod.DatpatcherProvider $，来自org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider $的ParameterValueHelper.getParameterValues（ParameterValueHelper.java:94） TypeOutInvoker.doDispatch（JavaResourceMethodDispatcherProvider.java:205）位于org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch（AbstractJavaResourceMethodDispatcher.java:99）org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke（ResourceMethodInvoker . java：389）org.glassfish.jersey.server.model.ResourceMethodInvoker.apply（ResourceMethodInvoker.java:347）at o rg.glassfish.jersey.server.model.ResourceMethodInvoker.apply（ResourceMethodInvoker.java:102）维持在org.glassfish.jersey.internal.Errors org.glassfish.jersey.server.ServerRuntime $ 2.run（ServerRuntime.java:326） $ 1.call（Errors.java:271）org.glassfish.jersey.internal.Errors $ 1.call（Errors.java:267）org.glassfish.jersey.internal.Errors.process（Errors.java:315）at at org.glassfish.jersey.internal.Errors.process（Errors.java:297）org.glassfish.jersey.internal.Errors.process（Errors.java:267）org.glassfish.jersey.process.internal.RequestScope . run orScope（RequestScope.java:317）org.glassfish.jersey.server.ServerRuntime.process（ServerRuntime.java:305）org.glassfish.jersey.server.ApplicationHandler.handle（ApplicationHandler.java:1154）atg.glassfish .jersey.servlet.WebComponent.serviceImpl（WebComponent.java:471）在org.glassfish.jersey.servlet.WebComponent.service（WebComponent.java:425）在org.glassfish.jersey.servlet.ServletContainer.service（ServletContainer.java ：383）在Org.glassfish.jersey.servlet.ServletContainer.service（ServletContainer.java:336）位于org.apache.catalina.core.ApplicationFilterChain.internalDoFilter的org.glassfish.jersey.servlet.ServletContainer.service（ServletContainer.java:223） ApplicationFilterChain.java:303）org.apache上的org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:208）org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52） org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:208）中的.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:241）org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java） ：220）org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:122）org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:501）org.apache.catalina.core . org.apache.catalina.valve上的StandardHostValve.invoke（StandardHostValve.java:171）位于org.apache.catalina.valves.AccessLogValve.invoke（AccessLogValve.java:950）的s.ErrorReportValve.invoke（ErrorReportValve.java:103）org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:116） org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:408）org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1070）org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process （AbstractProtocol.java:611）在java的java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1145）的org.apache.tomcat.util.net.JIoEndpoint $ SocketProcessor.run（JIoEndpoint.java:314） . 在java.lang.Thread.run（Thread . Java的：745）

e_mail是实体用户的主键 . 表名与类名用户相同As String电子邮件不是保存主键的好方法，我打算将其更改为int userId . 但问题对我来说仍然是一样的 .

我想要的是什么

class User : primary key=email, some other params
class BookForUser : primary key = id, some other params, foreign key = email

我所理解的是BookForUser没有完整的User对象 . 我不想要它 .

这种声明外键是否正确？ （我想要1个用户=很多预订）

如何将此电子邮件属性传递给我的Java代码？