Hi,

I'm having some problems in storing a Java HashMap.


<map name="hashMap" table="TextHashMap">
<key column="chvp"/>
<index column="idioma" type="string"/>
<element column="text" type="string"/>
</map>


What is the meaning of key, index and element? When i try to store the object i get a class cast exception to set the Property values os the element.

Thanks in advance,
Joao Rangel


java.lang.ClassCastException

at tipos.TipoDeContentorMetaClass4.setPropertyValues(<generated>)

at net.sf.hibernate.persister.AbstractEntityPersister.setPropertyValues(AbstractEntityPersister.java:162)

at net.sf.hibernate.impl.SessionImpl.doSave(SessionImpl.java:709)

at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:605)

at net.sf.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:1202)

Hi,

I forgot to mention another problem related with the previous post.

And if the HashMap is inside an object, which is a field of the persistent class? How can i store that HashMap in an assossiation table?


public class Objecto
{
private HashMap dataText = null;
...


public class StorableClass
{
private Integer chvp;
private String codigo;
private Objecto descricao;...


Thanks again,
Joao Rangel

The key, as for all collection mappings, is the column in the association table which identifies the map owner.

The index represent the column in the association table to be used as the index or key of the Map.

The element represents the column in the association table to be used as the element or value of the Map for the given index.


The map must be owned by a persistent class, so this question does not really make sense. Maybe I misunderstood what your asking?

As an example, say you have a class named Book and part of the Book class is a localized assoication to the contents of the book. The class looks something like:


And you want to map this content to an association table:
BOOK_CONTENT
----------------------------
BOOK_ID INTEGER
LOCALE VARCHAR(5)
CONTENT_LOCATION VARCHAR(4000)

That would look like:


After loading an instance of Book, the getLocalizedContent() method would return a Map of the book's content keyed by the locale for that particular content.