JPA：错误：尝试为 <MyClass> 类型重新创建文件

Question

每次运行我的代码时，都会出现以下错误：

 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.

一开始我以为是我不小心忘记添加子类，但它仍然给我同样的错误。ClubLes 继承自 Les，后者是一个仅包含 getter 的接口。我是否还需要使接口可序列化？我不知道出了什么问题。

俱乐部

@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() {
    }

接口

public interface Les {

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

PU
我只有一个持久化单元，看起来像这样

<?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>

我还注意到，当我从 JPA 中删除 clublesson 时，它会为 ClubPersoon 抛出相同的错误，它遵循相同的方案

Answer 1

我也遇到了这个错误，这是因为我在 pom.xml 中有依赖项和元模型插件配置，所以它们被生成了两次。尝试删除其中之一。

我的依赖配置：

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

我的插件配置：

<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>

Answer 2

尝试添加<exclude-unlisted-classes>true</exclude-unlisted-classes>到persistence.xml. 我认为由于缺少这个声明，这些类正在被处理两次。