@ManyToMany using Composite Key

Question

I have searched this forum concerning this issue. While I see others with a similar question, I see very little on a possible solution. Here is my problem statement.
Class 1: Document.java
Class 2: Collection.java
Class 3: CollectionType.java
XRef Table: Document_Collection
Relationships:
A DocumentID may be inside many collections.
A CollectionID may have many documents.
The owner of the relationship is document.java.
The collection table uses 3 fields for defining a Primary Key--Site, Name, and Date. The three fields are Strings.
I am using a SEQUENCE table for generating the unique Ids for each of the primary keys, except the Collection Table. This table is using a CompositePK Class for the Primary Key for the Collection Table.
Document.java:
@ManyToMany(cascade={CascadeType.ALL})
@JoinTable(name="DOCUMENT_COLLECTION",
                  joinColumns=@JoinColumn(name="DC_DOCUMENT_ID",           referencedColumnName="DOCUMENT_ID"),
       inverseJoinColumns={@JoinColumn(name="DC_COLLECTION_ID", referencedColumnName="SITE_ID"),
                                    @JoinColumn(name="DC_COLLECTION_ID", referencedColumnName="NAME"),
              @JoinColumn(name="DC_COLLECTION_ID", referencedColumnName="GROUP_DATE")}
public Set<Collection> getCollectionSet() {
          return collectionSet;
}Collection.java
@ManyToMany(mappedBy="collectionSet")
public Set<Document> getDocumentSet() {
     return documentSet;
}In the Collection Class it holds a reference to a Collection type.
CollectionType.java
@Id
@TableGenerator(name="COLLECTION_TYPE_TBL_GEN",
               table="SEQUENCE",
               pkColumnName="SEQ_NAME",
               valueColumnName="SEQ_COUNT",
               pkColumnValue="COLLECTION_TYPE_SEQ")
@GeneratedValue(strategy=GenerationType.TABLE,     generator="COLLECTION_TYPE_TBL_GEN")
@Column(name="COLLECTION_TYPE_ID", nullable=false)
public Long getCollectionTypeId() {
     return collectionTypeId;
}My test application builds the relationship for all the tables, and then attempts to persist the information to the database. When I look at at the log files, I see no errors, but the data is not being populated in the database. When I look at the SEQUENCE Table, I see all entries in the table are being incremented correctly except the Collection_Type sequence--still set to 1. I surmised the Collection Set for the Document_Collection table is not being populated correctly.
My intent is to let TopLink generate the PK, Ids for the objects. This appears to be happening for the one-to-one relationships but not for the ManyToMany relationships. When I build the relationships, I create the collection and CollectionType and add it to a set. This set is added to the Document class. Lastly, I call the persist method on the Entity Manager. The log file shows the sequence number is being generated except for the Collection_Type Sequence. This may not be the correct way, but I did not see the correct steps for accomplishing this operation.
[#|2007-08-27T16:52:03.899-0500|FINE|sun-appserver-pe9.0|oracle.toplink.essentials.file:/C:/glassfish/domains/domain1/applications/j2ee-apps/MyProject/MyEJB_jar/-MYEJBPU.sql|_ThreadID=12;_ThreadName=httpWorkerThread-8080-0;ClassName=null;MethodName=null;_RequestID=22dc7e71-9cef-4824-920f-5b3a2464c1d9;|SELECT SEQ_COUNT FROM SEQUENCE WHERE SEQ_NAME = ?
     bind => [URGENCY_SEQ]|#]This is how I build the Document Entity.
@TransactionAttribute(TransactionAttributeType.REQUIRED)
public Document addDocument(Document docVO) {
          entityManager.joinTransaction();
          Document doc = new Document();
          DataType dataType = getDataType(docVO.getDataType().getDescription());
          UrgencyIndicator urgency  = getUrgencyIndicator(docVO.getUrgencyIndicator().getCode());
          DocMetaData metadata = getDocMetadata(docVO.getDocMetadata().getStoragePath());
          WeaponsSystem weaponsSys = getWeaponsSystem(docVO.getWeaponsSystem().getCode());
          FileType fileType = getFileType(docVO.getFileType().getExtension());
          Date sqlDate = new Date(new java.util.Date().getTime());
          Set<Collection> collectSet = getDocumentCollection("Site", "Name", sqlDate.toString());
          doc.setUrgencyIndicator(urgency);
          doc.setDocMetadata(metadata);
          doc.setFileType(fileType);
          doc.setWeaponsSystem(weaponsSys);
          doc.setDataType(dataType);
          doc.setCollectionSet(collectSet);
          entityManager.persist(doc);
          return doc;
}Any suggestions would be greatly appreciated.
Russ

Answer 1

Okay I figured out one of my problems. When you search using the EntityManager's find method, a null is returned should JPA not be able to find an entity. This led to not populating the Collection Type and Collection incorrectly....... Now all Sequence generators are working correctly....... However, I am still not storing information in the database. Grrrrrr