Hibernate Unknown integral data type for ids

Hibernate Unknown integral data type for ids

When starting my spring boot application

@Entity
public class PlugMillingData {

   public PlugMillingData() {
      super();
   }

   @Id
   @GeneratedValue
   private String id;

  // Other infor....

I was getting the following error

Exception in thread "main" org.hibernate.id.IdentifierGenerationException: Unknown integral data type for ids : java.lang.String
    at org.hibernate.id.IdentifierGeneratorHelper.getIntegralDataTypeHolder(IdentifierGeneratorHelper.java:224)
    at org.hibernate.id.enhanced.SequenceStructure$1.getNextValue(SequenceStructure.java:98)
    at org.hibernate.id.enhanced.NoopOptimizer.generate(NoopOptimizer.java:40)
    at org.hibernate.id.enhanced.SequenceStyleGenerator.generate(SequenceStyleGenerator.java:432)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:105)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:675)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:667)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:662)
    at Main.main(Main.java:285)

Solution:

If you want String to be database key you need to use UUID to automatically generate key. Something like this:

@Entity
public class PlugMillingData {

   public PlugMillingData() {
      super();
   }

   @Id
   @GeneratedValue(generator="system-uuid")
   @GenericGenerator(name="system-uuid", strategy = "uuid")
   private String id;