CODEWITHSUNDEEP
springspring-boothibernatejpaspring-data-jpa
Oliver
Oliver

Reputation: 503

JPA @MappedSuperclass not working in Spring Boot

I am having trouble using the @MappedSuperclass annotation.

Here is a slimmed-down version that demonstrates my confusion.

Superclass:

import javax.persistence.Id;
import javax.persistence.MappedSuperclass;

@MappedSuperclass
public class FooBase {

  @Id
  protected Long id;

  // Getters/setters.

}

Subclass:

import javax.persistence.Entity;

@Entity
public class Foo extends FooBase {

  String bar;

  // Getters/setters.

}

I must be missing something here. Even IntelliJ reports the Foo class

Persistent entity 'Foo' should have primary key

And when I call JpaRepository#findAll(), the fields in Foo are not present in the JSON response entity.

[
    {
        "id": 1,
    }
]

Upvotes: 1

Views: 8401

Answers (5)

Oliver
Oliver

Reputation: 503

Thanks to all who answered my question.

My problem was not defining getters for subclass fields. Very silly mistake.

Upvotes: 5

Asaf Ben-Natan
Asaf Ben-Natan

Reputation: 39

usually that message

Persistent entity 'Foo' should have primary key

is received when the classes are not registered in the persistence.xml file. while some implementations do not even require persistence.xml file i have noticed that intelij will complain about it if its not there.

so i think creating a persistence.xml file (if you dont have one already) in your resources folder and set the following content

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             version="2.1"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="primary">

        <class>com.your.company.Foo</class>
        <class>com.your.company.Bar</class>
      


        <exclude-unlisted-classes>true</exclude-unlisted-classes>
    </persistence-unit>


</persistence>

Upvotes: 1

Monitoria
Monitoria

Reputation: 441

Try to set bar property to private.

Object returned by JPA call is probably proxy object. It's possible that the bar property is accessed directly instead of using getter when serialized to JSON.

Upvotes: 1

Santi Wagner
Santi Wagner

Reputation: 328

In order for a subclass to inherit fields from a MappedSuperClass, the access modifier must be at least protected or in any case, public.

Upvotes: 1

Ajay Negi
Ajay Negi

Reputation: 330

Check your pom file, it should look something like this:

<project
xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org /xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
    <groupId>net.javaguides.hibernate</groupId>
    <artifactId>hibernate-tutorial</artifactId>
    <version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>hibernate-mappedsuperclass-example</artifactId>
<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.13</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.3.7.Final</version>
    </dependency>
</dependencies>
<build>
    <sourceDirectory>src/main/java</sourceDirectory>
    <plugins>
        <plugin>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.5.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>
</project>

Upvotes: -1

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