tutorial 3 afterStore() instance callback updated for version 1.0

[Brian Chaplin <bc...@chaplinsolutions.com>]

I updated the code in this tutorial to run with version 1.0:

public abstract class DBAutoIncremented
 implements  PersistenceBrokerAware {

 private static final String ID_ATTRIBUTE_NAME = "m_id";


 public void afterDelete(PersistenceBroker broker)
  throws PersistenceBrokerException {
 }

 public void afterInsert(PersistenceBroker broker)
  throws PersistenceBrokerException {

  // remove object from cache to ensure we are retrieving a
  // copy that is in sync with the database.
  broker.removeFromCache(this);

  Class clazz = getClass();
  ClassDescriptor cld = broker.getClassDescriptor(clazz);
  PersistentField idField =
   cld
    .getFieldDescriptorByName(ID_ATTRIBUTE_NAME)
    .getPersistentField();

  if (hasNotBeenSet(idField)) {

   // retrieve the object again with a query
   // on all non-id attributes.
   Object object =
    broker.getObjectByQuery(
     buildQueryOnAllNonIdAttributes(clazz, cld));

   if (object == null) {
    throw new PersistenceBrokerException(
     "cannot assign ID to "
      + this
      + " ("
      + clazz
      + ")"
      + " because lookup by attributes failed");
   }

   // set id attribute with the value
   // assigned by the database.
   idField.set(this, idField.get(object));
  }

 }

 public void afterLookup(PersistenceBroker broker)
  throws PersistenceBrokerException {
 }

 public void afterUpdate(PersistenceBroker broker)
  throws PersistenceBrokerException {

 }

 public void beforeDelete(PersistenceBroker broker)
  throws PersistenceBrokerException {
 }

 public void beforeInsert(PersistenceBroker broker)
  throws PersistenceBrokerException {

 }

 public void beforeUpdate(PersistenceBroker broker)
  throws PersistenceBrokerException {
 }

 /**
 * after storing a new instance reflect the
 * autoincremented PK value
 * back into the PK attribute.
 */
 public void afterStore() {
  PersistenceBroker broker =
   PersistenceBrokerFactory.defaultPersistenceBroker();

  try {
   // remove object from cache to ensure we are retrieving a
   // copy that is in sync with the database.
   broker.removeFromCache(this);

   Class clazz = getClass();
   ClassDescriptor cld = broker.getClassDescriptor(clazz);
   PersistentField idField =
    cld
     .getFieldDescriptorByName(ID_ATTRIBUTE_NAME)
     .getPersistentField();

   if (hasNotBeenSet(idField)) {

    // retrieve the object again with a query
    // on all non-id attributes.
    Object object =
     broker.getObjectByQuery(
      buildQueryOnAllNonIdAttributes(clazz, cld));

    if (object == null) {
     throw new PersistenceBrokerException(
      "cannot assign ID to "
       + this
       + " ("
       + clazz
       + ")"
       + " because lookup by attributes failed");
    }

    // set id attribute with the value
    // assigned by the database.
    idField.set(this, idField.get(object));
   }
  } finally {
   PersistenceBrokerFactory.releaseAllInstances();
  }
 }

 /**
  * returns a query that identifies an object by all its non-
  * primary key attributes.
  * this method is only safe, if these values are unique!
  */
 private Query buildQueryOnAllNonIdAttributes(
  Class clazz,
  ClassDescriptor cld) {

  // note: these are guaranteed to be in the same order
  FieldDescriptor[] fields = cld.getFieldDescriptions();
  Criteria crit = new Criteria();

  for (int i = 0; i < fields.length; i++) {
   if (!fields[i].getAttributeName().equals(ID_ATTRIBUTE_NAME)) {
    Object value = fields[i].getPersistentField().get(this);
    if (value == null) {
     crit.addIsNull(fields[i].getAttributeName());
    } else {
     crit.addEqualTo(fields[i].getAttributeName(), value);
    }
   }
  }
  return QueryFactory.newQuery(clazz, crit);
 }

 /**
  * returns true if attribute idField == 0,
  * else false.
  */
 private boolean hasNotBeenSet(PersistentField idField) {
  return (((Integer) idField.get(this)).intValue() == 0);
 }

}