Vfrdtyky

I have a couple of services who use the same form of table to store translations, so I moved the translation entity into a shared project and try to have a unidirectional @OneToMany mapping on that entity. However I keep getting following exception
Caused by: org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: com.examples.blog.Post.translations[com.examples.shared.domain.Translation]


my Post class looks like this

package com.examples.blog.domain;



import com.examples.shared.domain.Translation;

import lombok.AllArgsConstructor;

import lombok.Builder;

import lombok.Data;

import lombok.NoArgsConstructor;

import org.hibernate.annotations.GenericGenerator;



import javax.persistence.*;

import java.io.Serializable;

import java.util.List;



@Data

@Entity

@Table(name = "POSTS")

@Builder

@NoArgsConstructor

@AllArgsConstructor

public class Currency implements Serializable {



    @Id

    @GeneratedValue(generator = "system-uuid")

    @GenericGenerator(name = "system-uuid", strategy = "uuid")

    private String id;



    private String author;



    @Embedded

    private Source source;



    @OneToMany(cascade = CascadeType.ALL,

        orphanRemoval = true)

    @JoinColumn(name = "entity_id")

    List<Translation> translations;



}

and my shared Translation class looks like this:

package com.examples.shared.domain;



import lombok.AllArgsConstructor;

import lombok.Builder;

import lombok.Data;

import lombok.NoArgsConstructor;

import org.hibernate.annotations.GenericGenerator;



import javax.persistence.*;

import java.io.Serializable;



@Entity

@Table(name = "TRANSLATIONS")

@Data

@Builder(toBuilder = true)

@NoArgsConstructor

@AllArgsConstructor

public class Translation implements Serializable {



    @Id

    @GeneratedValue(generator = "system-uuid")

    @GenericGenerator(name = "system-uuid", strategy = "uuid")

    private String id;



    @Column(name = "language")

    private String language;



    @Column(name="translation")

    private String translation;



    @Column(name="entity_id")

    @ManyToOne

    private String entityId;



}

Anyone can help me figure out what I'm doing wrong here?

Seems like hibernate is not aware of com.examples.shared.domain.Translation entity.
You should provide hibernate a list of classes or packages where it should look for @Entities classes.

If you use Spring Boot use @EntityScan(basePackages="com.examples.shared.domain").

If you use Spring + Hibernate integration, use LocalContainerEntityManagerFactoryBean.setPackagesToScan("com.examples.shared.domain")

If you use plain hibernate, add a corresponding entry to persistence.xml or hibernate.cfg.xml:

<hibernate-configuration>

    ....

    <mapping class="com.examples.shared.domain.Translation"/>

 </session-factory>

</hibernate-configuration>

Or for java config see docs: http://docs.jboss.org/hibernate/orm/5.3/userguide/html_single/Hibernate_User_Guide.html#bootstrap-bootstrap-native-registry-MetadataSources-example

Below statement is causing you issue:

  @Column(name="entity_id")

    @ManyToOne

    private String entityId;

Instead of String entityId, you should mention relationship with a valid entity class. Here entityId is of type String which is obviously not a declared entity.

You are mapping 2nd class in onetomany in one class but mapping manytoone to a string instead of class.

Change

@ManyToOne

private String entityId;

to

@ManyToOne

private Currency entityId;

See this