CODEWITHSUNDEEP
javamysqlhibernatejpaclob
Sebastian Lang
Sebastian Lang

Reputation: 492

JPA persisting does not happen with relation when VARCHARS turn to CLOBs

I do have two entities that relate each other via a OneToMany-Relation.

Entity 1 is named "Change" and looks like the following

public class Change {

  String attribute1;

  @Column(name="\"ATTRIBUTE1\"")
  public void getAttribute1() {
    return this.attribute1;
  }

  public void setAttribute1(String attribute1) {
    this.attribute1 = attribute1;
  }

  // and 7 more of these....

  List<ChangeTask> relatedChangeTasks = new ArrayList<ChangeTask>();

  @OneToMany(cascade={PERSIST, MERGE, REFRESH}
  @JoinTable(name="CHANGE_CHANGETASK", joinColumns={@JoinColumn(name="CHANGE_ID")}, inverseJoinColumns={@JoinColumn(name="CHANGETASK_ID")})
  @JoinColumn(name="\"relatedChangeTask_ID\"" )

  public List<ChangeTask> getRelatedChangeTasks() {
    return this.relatedChangeTasks;
  }

  public void setRelatedChangeTasks(List<ChangeTask> relatedChangeTasks) {
    this.relatedChangeTasks = relatedChangeTasks;
  }
}

Entity 2 is named ChangeTask and extends Change.

public class ChangeTask extends Change {

  // some additional attributes...
}

Persisting a new or existing Change record with one ChangeTask added to the "relatedChangeTask" list works just perfect.

Now I have to change the annotation of the 8 attributes from Default to @Lob, so Change now looks like this:

  public class Change {

  String attribute1;

  @Lob
  @Column(name="\"ATTRIBUTE1\"")
  @Basic(fetch=EAGER)

  public String getAttribute1() {
    if(fieldHandler != null) {
      return (java.lang.String) fieldHandler.readObject(this, "attribute1", attribute1);
    }
    return attribute1;
  }

  public void setAttribute1(String attribute1) {
    if(fieldHandler != null) {
      this.attribute1= (java.lang.String) fieldHandler.writeObject(this, "attribute1", this.attribute1, attribute1);
      return;
    }
    this.attribute1= attribute1;
  }      

  // and 7 more of these....

  List<ChangeTask> relatedChangeTasks = new ArrayList<ChangeTask>();

  @OneToMany(cascade={PERSIST, MERGE, REFRESH}
  @JoinTable(name="CHANGE_CHANGETASK", joinColumns={@JoinColumn(name="CHANGE_ID")}, inverseJoinColumns={@JoinColumn(name="CHANGETASK_ID")})
  @JoinColumn(name="\"relatedChangeTask_ID\"" )

  public List<ChangeTask> getRelatedChangeTasks() {
    return this.relatedChangeTasks;
  }

  public void setRelatedChangeTasks(List<ChangeTask> relatedChangeTasks) {
    this.relatedChangeTasks = relatedChangeTasks;
  }
}

Now, when I try to add a given ChangeTask to a Change the persist operation does not fail. But at the end of the Transaction the relation has not been persisted, meaning the relation-table "CHANGE_CHANGETASK" remains empty. When I debug through the whole process, I can see that the list contains one entry before "entityManager.merge()" operation and it still contains one entry after the merge. But it never arrives at the database.

Does anybody have an idea what I'm doing wrong here? As strange as it may sound, it must be something related with the @Lob annotations. As soon as I remove those again from the entity everything works fine.

Thanks in advance.

Upvotes: 0

Views: 36

Answers (1)

fhossfel
fhossfel

Reputation: 2181

You wrote

public void getAttribute1() {

That can't be right. I think you mean

public String getAttribute1() {

Additionally you have annotated the setter:

@Column(name="\"ATTRIBUTE1\"")
public void setAttribute1(String attribute1) {
  this.attribute1 = attribute1;
}

You have to annotage either the field or the getter.

Upvotes: 1

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