My domain model in my Java EE 6 application contains bi-directional relationships like the following:
@Entity
public class Users implements PrimaryKeyHolder<String>, Serializable {
@Id
private String username;
@ManyToMany(mappedBy= "users")
private List<Category> categories;
public List<Category> getCategories() {
if (categories == null) {
categories = new ArrayList<Category>();
}
return Collections.unmodifiableList(categories);
}
public void addCategory(Category category) {
if (categories == null) {
categories = new ArrayList<Category>();
}
categories.add(category);
if (!category.getUsers().contains(this)) {
category.addUser(this);
}
}
public void removeCategory(Category category) {
if (categories == null) {
categories = new ArrayList<Category>();
}
categories.remove(category);
if (category.getUsers().contains(this)) {
category.removeUser(this);
}
}
public void setCategories(Collection<Category> categories) {
if (this.categories == null) {
this.categories = new ArrayList<Category>();
}
for (Iterator<Category> it = this.categories.iterator(); it.hasNext();) {
Category category = it.next();
it.remove();
if (category.getUsers().contains(this)) {
category.removeUser(this);
}
}
for (Category category : categories) {
addCategory(category);
}
}
}
@Entity
public class Category implements PrimaryKeyHolder<Long>, Serializable {
@Id
private Long id;
@ManyToMany
private List<User> users;
public List<User> getUsers() {
if (users == null) {
users = new ArrayList<User>();
}
return Collections.unmodifiableList(users);
}
protected void addUser(User user) {
if (users == null) {
users = new ArrayList<User>();
}
users.add(user);
}
protected void removeUser(User user) {
if (users == null) {
users = new ArrayList<User>();
}
users.remove(user);
}
}
UPDATE: I added relationship management code. Relationships are only set on the user side, therefore, the add/remove methods are protected in the Categoriy class. I set the categories on the user via setCategories.
Eclipselink correctly generates a join table CATEGORY_USERS. However, it does not persist any information in it (it only caches the information). E.g. when I execute a find operation on the entity manager (e.g. a user), it returns the complete object graph (including the category relationship). But when I look at the tables, information are not updated (even though the transactions are committed). I also inserted a flush operation in my code, without success. Basic information (like String, Integer, etc. columns) gets correctly persisted and updated. After turning the log level to FINE, I can see that no SQL statements are executed for the relationships and the join table, respectively. But I do see SQL statements for uni-directional relationships.
My datamodel is covered by extensive unit tests, which all pass successfully. I basically do the same operation as in the container, commit the transaction, reload the entities from the db and check if the relationships are correctly set, which they are (I'm using the in-memory derby database for testing).
My app server is Glassfish v3.1-b17.
Any help is appreciated. Thanks, Theo