JPA: Error: Attempt to recreate a file for type <MyClass>

Question

Every time I run my code, I get the following error:

 java.lang.RuntimeException: javax.annotation.processing.FilerException: Attempt to recreate a file for type domein.ClubLes_
    [javac]     at org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor.process(CanonicalModelProcessor.java:407)
    [javac]     at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:964)
    [javac]     at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:881)
    [javac]     at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.access$2100(JavacProcessingEnvironment.java:110)
    [javac]     at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1202)
    [javac]     at jdk.compiler/com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1311)
    [javac]     at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1250)
    [javac]     at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:928)
    [javac]     at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:306)
    [javac]     at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:165)
    [javac]     at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
    [javac]     at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)
    [javac] Caused by: javax.annotation.processing.FilerException: Attempt to recreate a file for type domein.ClubLes_
    [javac]     at jdk.compiler/com.sun.tools.javac.processing.JavacFiler.checkNameAndExistence(JavacFiler.java:727)
    [javac]     at jdk.compiler/com.sun.tools.javac.processing.JavacFiler.createSourceOrClassFile(JavacFiler.java:489)
    [javac]     at jdk.compiler/com.sun.tools.javac.processing.JavacFiler.createSourceFile(JavacFiler.java:426)
    [javac]     at org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor.generateCanonicalModelClass(CanonicalModelProcessor.java:98)
    [javac]     at org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor.generateCanonicalModelClasses(CanonicalModelProcessor.java:226)
    [javac]     at org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor.process(CanonicalModelProcessor.java:403)
    [javac]     ... 11 more

BUILD FAILED
E:\ProjectJava\java-g11\Taijitan\nbproject\build-impl.xml:1134: The following error occurred while executing this line:
E:\ProjectJava\java-g11\Taijitan\nbproject\build-impl.xml:381: Compile failed; see the compiler error output for details.

At first I thought it was because I accidently forgot to add the subclass, but it's still giving me the same error. ClubLes inherits from Les, which is an interface which contains only getters. Do I need to make the interface serializable aswell? I have no idea what's going wrong.

ClubLes

@Entity
public class ClubLes implements Serializable, Les {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "LesId")
    private int id;
    @Column(name = "Naam")
    String naam;
    @Column(name = "Soort")
    String soort;
    @ManyToOne
    @JoinColumn(name = "GraadNumeriek")
    Graad graad;
    @Column(name = "FotoUrl")
    private String fotoUrl;
    @Column(name = "Beschrijving")
    private String beschrijving;
    @Column(name = "VideoUrl")
    private String videoUrl;

    public ClubLes() {
    }

Les interface

public interface Les {

    int getId();
    String getNaam();
    String getSoort();
    //More getters
}

PU
I only have one persistence unit, which looks like this

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
  <persistence-unit name="TaijitanPU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <class>domein.Graad</class>
    <class>domein.Locatie</class>
    <class>domein.ClubPersoon</class>
    <class>domein.ClubActiviteit</class>
    <class>domein.ClubLes</class>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:sqlserver://localhost:1433;databaseName=Taijitan"/>
      <property name="javax.persistence.jdbc.user" value="sa"/>
      <property name="javax.persistence.jdbc.driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver"/>
      <property name="javax.persistence.jdbc.password" value="Wachtwoord2019"/>
      <property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
    </properties>
  </persistence-unit>
</persistence>

I also noticed that when I remove clublesson from JPA, it throws the same error for ClubPersoon, which follows the same scheme

Answer 1

I had this error also, and it was because I had the dependency and the metamodel plugin configuration in the pom.xml, so they were being generated twice. Try removing one of them.

My dependency configuration:

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-jpamodelgen</artifactId>
    <scope>provided</scope>
</dependency>

My plugin configuration:

<plugin>
    <groupId>org.bsc.maven</groupId>            
    <artifactId>maven-processor-plugin</artifactId>
    <version>4.5</version>
    <executions>            
        <execution>         
          <id>process</id>          
              <goals>           
                <goal>process</goal>            
              </goals>          
              <phase>generate-sources</phase>           
              <configuration>           
                <!-- source output directory -->            
                <outputDirectory>target/metamodel</outputDirectory>         
              </configuration>          
            </execution>            
        </executions>           
</plugin>           
<plugin>            
    <groupId>org.codehaus.mojo</groupId>            
    <artifactId>build-helper-maven-plugin</artifactId>  
    <executions>            
      <execution>           
        <id>add-source</id>         
        <phase>generate-sources</phase>         
        <goals>         
          <goal>add-source</goal>           
        </goals>            
        <configuration>         
          <sources>         
            <source>target/metamodel</source>           
          </sources>            
        </configuration>
    </execution>            
  </executions>         
</plugin>