使用jackson的spring boot坚持嵌套实体失败答案

【问题标题】：spring boot using jackson persist of nested entity failing使用jackson的spring boot坚持嵌套实体失败
【发布时间】：2017-04-07 19:25:52
【问题描述】：

我正在处理我的第一个 spring-boot 项目。我有两个实体，其中一个依赖于另一个。

这是插入数据的 JSON

{
  "city": "Chicago",
  "description": "scattered clouds",
  "humidity": 33,
  "pressure": 1020,
  "temperature": 25,
  "wind": {
    "speed": 3.1,
    "degree": 240
  },
  "timestamp": "2017-02-14T05:48:41.861Z"
}

如您所见，风有一个单独的实体。

第一个实体是 WeatherSensor

@Entity
public class WeatherSensor {

    public WeatherSensor() {
        this.id = UUID.randomUUID().toString();
    }




    @Id
    private String id;
    private String city;
    private String description;
    private int humidity;
    private int pressure;
    private int temperature;
    private Timestamp timestamp;
    @OneToOne
    private Wind wind;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "WeatherSensor [city=" + city + ", description=" + description + ", humidity=" + humidity + ", pressure="
                + pressure + ", temperature=" + temperature + ", timestamp=" + timestamp + ", wind=" + wind + "]";
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public int getHumidity() {
        return humidity;
    }

    public void setHumidity(int humidity) {
        this.humidity = humidity;
    }

    public int getPressure() {
        return pressure;
    }

    public void setPressure(int pressure) {
        this.pressure = pressure;
    }

    public int getTemperature() {
        return temperature;
    }

    public void setTemperature(int temperature) {
        this.temperature = temperature;
    }

    public Timestamp getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(Timestamp timestamp) {
        this.timestamp = timestamp;
    }

    public Wind getWind() {
        return wind;
    }

    public void setWind(Wind wind) {
        this.wind = wind;
    }

}

第二个实体是风

@Entity
public class Wind {

    public Wind() {
        this.id = UUID.randomUUID().toString();
    }

    @Id
    private String id;

    private float speed;
    private int degree;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public float getSpeed() {
        return speed;
    }

    public void setSpeed(float speed) {
        this.speed = speed;
    }

    public int getDegree() {
        return degree;
    }

    public void setDegree(int degree) {
        this.degree = degree;
    }

    @Override
    public String toString() {
        return "Wind [speed=" + speed + ", degree=" + degree + "]";
    }

}

这里是异常堆栈

2017-04-07 12:30:32.631 ERROR 12282 --- [nio-9000-exec-1] o.a.c.c.C.[.[.[.[dispatcherServlet]      : Servlet.service() for servlet [dispatcherServlet] in context with path [/api] threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaObjectRetrievalFailureException: Unable to find io.egen.api.entity.Wind with id 5e022f73-3815-4b9f-84bb-5cad4e173112; nested exception is javax.persistence.EntityNotFoundException: Unable to find io.egen.api.entity.Wind with id 5e022f73-3815-4b9f-84bb-5cad4e173112] with root cause

javax.persistence.EntityNotFoundException: Unable to find io.egen.api.entity.Wind with id 5e022f73-3815-4b9f-84bb-5cad4e173112
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$JpaEntityNotFoundDelegate.handleEntityNotFound(EntityManagerFactoryBuilderImpl.java:144) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultLoadEventListener.load(DefaultLoadEventListener.java:227) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:278) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultLoadEventListener.doOnLoad(DefaultLoadEventListener.java:121) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:89) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.internal.SessionImpl.fireLoad(SessionImpl.java:1129) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.internal.SessionImpl.internalLoad(SessionImpl.java:1022) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.type.EntityType.resolveIdentifier(EntityType.java:639) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.type.EntityType.resolve(EntityType.java:431) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.type.EntityType.replace(EntityType.java:330) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.type.AbstractType.replace(AbstractType.java:147) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.type.TypeHelper.replace(TypeHelper.java:211) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.copyValues(DefaultMergeEventListener.java:438) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.entityIsTransient(DefaultMergeEventListener.java:233) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.entityIsDetached(DefaultMergeEventListener.java:301) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:170) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:69) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:840) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:822) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:827) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:1161) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
    at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:347) ~[spring-orm-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at com.sun.proxy.$Proxy70.merge(Unknown Source) ~[na:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:298) ~[spring-orm-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at com.sun.proxy.$Proxy70.merge(Unknown Source) ~[na:na]
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:511) ~[spring-data-jpa-1.11.1.RELEASE.jar:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:504) ~[spring-data-commons-1.13.1.RELEASE.jar:na]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:489) ~[spring-data-commons-1.13.1.RELEASE.jar:na]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:461) ~[spring-data-commons-1.13.1.RELEASE.jar:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) ~[spring-data-commons-1.13.1.RELEASE.jar:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282) ~[spring-tx-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.3.7.RELEASE.jar:4.3.7.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:133) ~[spring-data-jpa-1.11.1.RELEASE.jar:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:57) ~[spring-data-commons-1.13.1.RELEASE.jar:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at com.sun.proxy.$Proxy72.save(Unknown Source) ~[na:na]
    at io.egen.api.serviceImpl.WeatherServiceImpl.save(WeatherServiceImpl.java:20) ~[classes/:na]
    at io.egen.api.controller.WeatherController.save(WeatherController.java:29) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:648) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_121]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_121]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_121]

我必须确保首先从 JSON 中将 Wind 数据添加到 WInd 表中，然后使用创建的 Id 使用剩余的值更新 WeatherSensor。如果我缺少注释或方法，请提供帮助。

编辑：-

这里是控制器

@RestController
@CrossOrigin
public class WeatherController {
    private WeatherService weatherService;

    public WeatherController(WeatherService weatherService) {
        this.weatherService = weatherService;
    }

    // @RequestMapping(method = RequestMethod.GET)
    // public String home() {
    // return "welcome!";
    // }

    @RequestMapping(method = RequestMethod.POST, value = "save")
    public WeatherSensor save(@RequestBody WeatherSensor weatherSensor) {
        System.out.println(weatherSensor.toString());
        weatherService.save(weatherSensor);

        return weatherSensor;
    }}

这里是 application.properties

server.port=9000
server.context-path=/api

#database setup
spring.datasource.url=jdbc:mysql://localhost:3306/clearsky?useSSL=false
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.show-sql=true

这是我要命中的端点：-

http://localhost:9000/api/save

请帮忙！

【问题讨论】：

你是如何插入那个 json 文件的？
我正在使用邮递员及其 POST 命令
是的，但是您正在访问端点（可能是一个 servlet）。能贴出处理数据的方法的代码吗？
@Hackerman 在主要问题中添加了控制器和 aplication.properties 文件。
我想我正在寻找的只是如何解析 JSON 以获取 Wind 相关信息，将其添加到 Wind 表并使用 Wind 中的 UUID 将数据添加到 WeatherSensor。我想我错过了一些注释。

标签： java json spring spring-boot jackson

【解决方案1】：

问题是总是在您的实体中生成新的 UUID 作为标识符。

EntityManager merge 对分离的对象有一些神奇的作用。

Merge 创建实体的新实例，从提供的实体复制状态，并管理新副本。

但是新实例有一个新的不同的 id，这意味着它不能被原始 id 找到。

要解决此问题，请在您的实体/构造函数之外生成 UUID。

【讨论】：

【解决方案2】：

我认为您必须先保存 Wind 实体，然后才能将其链接到 WeatherSensor 实体。例如，在您的服务层中，保存方法可以是：

class WeatherServiceTemplate implements WeatherService{
      @Autowired
      private WeatherSensorRepository weatherSensorRepo;
      @Autowired
      private WindRepository windRepo;

      public WeatherSensor save(WeatherSensor weatherSensor){
             windRepo.save(weatherSensor.getWind());
             return weatherSensorRepo.save(weatherSensor);
      }
}

【讨论】：

我没有 Wind 的存储库，因为它本身没有任何个人存在。当要持久保存天气传感器中的新条目时，将始终创建它。
要使@OneToOne 关系发挥作用，它需要一个实体被持久化