java - @Embeddables 的 @ElementCollection 每个都有 @Embeddable 字段会导致 "Could not find a setter"异常

Question

我有实体 Ride 和 @ElementCollection(targetClass = RideLocation.class):

@ElementCollection(targetClass = RideLocation.class)
    @CollectionTable(name = "ride_locations", joinColumns = @JoinColumn(name = "ride_id"))
    List<RideLocation> locations = new ArrayList<>();

RideLocation 是 @Embeddable，其中包含另一个 @Embeddable:

@Embeddable
public class RideLocation {

    @Column(name = "timestamp")
    long timestamp;

    @Embedded
    Location location;

    public RideLocation(long timestamp, Location location) {
        Assert.isTrue(timestamp > 0);
        Assert.notNull(location);
        this.timestamp = timestamp;
        this.location = location;
    }

    RideLocation() {
    }

    public long getTimestamp() {
        return timestamp;
    }

    public Location getLocation() {
        return location;
    }

}

位置是@Embeddable本身:

@Embeddable
public class Location {

    @Column(name = "address")
    String address;

    @Type(type = "org.hibernate.spatial.GeometryType")
    @Column(name = "point", columnDefinition = "geometry")
    Point point;

    public Location(double lat, double lng, String address) {
        this.point = wktToPoint(String.format("POINT(%.6f %.6f)", lng, lat));
        this.address = address;
    }

    Location() {
    }

    public String getAddress() {
        return address;
    }

    public Point getPoint() {
        return point;
    }

    @Transient
    public double getLat() {
        return point.getY();
    }

    @Transient
    public double getLng() {
        return point.getX();
    }

    private Point wktToPoint(String wktPoint) {
        WKTReader fromText = new WKTReader();
        Geometry geom = null;
        try {
            geom = fromText.read(wktPoint);
        } catch (ParseException e) {
            throw new RuntimeException("Not a WKT string:" + wktPoint);
        }
        geom.setSRID(4326);
        return (Point) geom;
    }

}

看起来不错，但是这个配置给了我一个异常“无法在类 Location 中找到属性地址的 setter ”。

这对我来说看起来很奇怪，因为 Location 的任何属性都不需要 setter ，直到我尝试在另一个 @Embeddable 中使用它
是 ElementCollection 的目标。

即无法正确加载集合内的第二级@embeddable。

UPD 堆栈跟踪如下所示:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class com.dropbyke.application.JpaConfig: Invocation of init method failed; nested exception is org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.component.PojoComponentTuplizer]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1566)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:956)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:747)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:321)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:961)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:950)
    at com.dropbyke.web.api.DropbykeApi.main(DropbykeApi.java:69)
    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:497)
    at org.springsource.loaded.ri.ReflectiveInterceptor.jlrMethodInvoke(ReflectiveInterceptor.java:1270)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.component.PojoComponentTuplizer]
    at org.hibernate.tuple.component.ComponentTuplizerFactory.constructTuplizer(ComponentTuplizerFactory.java:101)
    at org.hibernate.tuple.component.ComponentTuplizerFactory.constructDefaultTuplizer(ComponentTuplizerFactory.java:122)
    at org.hibernate.tuple.component.ComponentMetamodel.<init>(ComponentMetamodel.java:81)
    at org.hibernate.mapping.Component.getType(Component.java:180)
    at org.hibernate.tuple.PropertyFactory.buildStandardProperty(PropertyFactory.java:353)
    at org.hibernate.tuple.component.ComponentMetamodel.<init>(ComponentMetamodel.java:71)
    at org.hibernate.mapping.Component.getType(Component.java:180)
    at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:310)
    at org.hibernate.mapping.Collection.validate(Collection.java:315)
    at org.hibernate.mapping.Set.validate(Set.java:40)
    at org.hibernate.cfg.Configuration.validate(Configuration.java:1362)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1849)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:852)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:845)
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:399)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:844)
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:343)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:318)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1625)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1562)
    ... 21 common frames omitted
Caused by: java.lang.reflect.InvocationTargetException: null
    at sun.reflect.GeneratedConstructorAccessor28.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at org.springsource.loaded.ri.ReflectiveInterceptor.jlrConstructorNewInstance(ReflectiveInterceptor.java:1002)
    at org.hibernate.tuple.component.ComponentTuplizerFactory.constructTuplizer(ComponentTuplizerFactory.java:98)
    ... 41 common frames omitted
Caused by: org.hibernate.PropertyNotFoundException: Could not find a setter for property address in class com.dropbyke.domain.Location
    at org.hibernate.property.BasicPropertyAccessor.createSetter(BasicPropertyAccessor.java:246)
    at org.hibernate.property.BasicPropertyAccessor.getSetter(BasicPropertyAccessor.java:240)
    at org.hibernate.mapping.Property.getSetter(Property.java:328)
    at org.hibernate.tuple.component.PojoComponentTuplizer.buildSetter(PojoComponentTuplizer.java:159)
    at org.hibernate.tuple.component.AbstractComponentTuplizer.<init>(AbstractComponentTuplizer.java:65)
    at org.hibernate.tuple.component.PojoComponentTuplizer.<init>(PojoComponentTuplizer.java:59)

Answer 1

我很确定它在提示，因为你有一个带有 getter 的字段 Address，但没有 setter。 JPA 足够“聪明”，可以假设以“is”和“get”开头的方法也需要相同 val 的“set”函数。因此添加一个“setAddress”，它就会停止提示。

要在不创建 setter 的情况下修复此问题，只需将该方法标记为“@Transient”即可。确保导入 javax.persistence.Transient 而不是 java.beans.Transient，否则仍然会失败。