Mapping a ManyToMany relationship with hibernate annotations?

Question

Table Layout:

TABLE ORDER:
id 
localizedInfoId

Table OrderLocalizedInfo:
id
localizedInfoId
name

With the following entities:

public class Order {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="id")
   private Long id;

    @ManyToMany(
        targetEntity=OrderLocalizedInfo.class,
        cascade={CascadeType.PERSIST, CascadeType.MERGE})
    @JoinTable(
        name="OrderLocalizedInfo",
        joinColumns=@JoinColumn(name="localizedInfoId"),
        inverseJoinColumns=@JoinColumn(name="localizedInfoId"))
   private List localizedInfos;
}

public class OrderLocalizedInfo {

   @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="id")
   private Long id;

    @Column(name="localizedInfoId")
   private Long localizedInfoId;

    @Column(name="name")
   private String name;
}

I want to map the above situation so that I have a list of OrderLocalizedInfo objects on the order object, using the 'localizedInfoId' field in each table. When I do this I get a mapping exception 'Repeated column mapping for collection Order.localizedInfos column: localizedInfoId.

Answer 1

I don't really understand your physical model but it clearly doesn't represent a many to many association. A many to many association between A and B involves a join table that contains columns for the primary keys of the source and target tables:

+-------+    +-------+    +-------+
|   A   |    |  A_B  |    |   B   |
+-------+    +-------+    +-------+
| A_ID  |    | AID   |    | B_ID  |
| ...   |    | BID   |    | ...   |
+-------+    +-------+    +-------+

So currently, there is nothing to map with @ManyToMany. You need to either fix your physical model or clarify what you're trying to achieve (maybe it's not a many to many after all).

Answer 2

As Pascal said, there isn't a ManyToMany relationship present as shown. Your current model suggesting a List of OrderLocalizedInfo objects would be better represented in Hibernate as a OneToMany Collection - http://docs.jboss.org/hibernate/core/3.5/reference/en/html/collections.html