Generate mapping files from pre-existing POJO java files

Hibernate Tools
1

Hello Experts,

I am looking forward for a way to generate mapping files from pre-existing JAVA classes. JAVA files for these classes don’t have any annotations, but they have some kind of hierarchy.
I know that it is possible to generate mapping files from DB tables, but I don’t have any pre-existing DB tables, but would like to create them using mapping file.

Thanks,
Kailas

2

Hi @Kailas_Phanashikar - probably you are looking for something like that :slight_smile:
org.hibernate.tool.hbm2ddl.SchemaExport;
org.hibernate.tool.schema.TargetType;

private void export() {
SchemaExport export = new SchemaExport();
export.setOutputFile(OUTPUT_FILE);
export.setFormat(true);
export.setDelimiter(";");
EnumSet types = EnumSet.of(TargetType.SCRIPT);
Metadata metadata = createMetadataSources().buildMetadata();
export.execute(types, SchemaExport.Action.CREATE, metadata);
}

private MetadataSources createMetadataSources() {
MetadataSources metadata =
new MetadataSources(new StandardServiceRegistryBuilder()
.applySetting(“hibernate.dialect”, DIALECT)
.build());

for (String entityPackage : entityPackages) {
  final Reflections reflections = new Reflections(entityPackage);
  for (Class<?> cl :
       reflections.getTypesAnnotatedWith(MappedSuperclass.class)) {
    metadata.addAnnotatedClass(cl);
    log.info(String.format("Mapped = %s", cl.getName()));
  }
  for (Class<?> cl : reflections.getTypesAnnotatedWith(Entity.class)) {
    metadata.addAnnotatedClass(cl);
    log.info(String.format("Mapped = %s", cl.getName()));
  }
}
return metadata;

}

3

Hi @Kailas_Phanashikar,
You say your classes are NOT annotated? For sure not every class in your project represents an entity? Or can you give an example of the class structure for which you want to do this?
Cheers,
Koen