import org.kuali.rice.krad.service.util.OjbCollectionAware; //导入依赖的package包/类
/**
 * This method identifies items in the first List that are not contained in the second List. It is similar to the (optional)
 * java.util.List retainAll method.
 *
 * @param fromList    list from the database
 * @param controlList list from the object
 * @return true iff one or more items were removed
 */
private List findUnwantedElements(Collection fromList, Collection controlList, OjbCollectionAware template, int depth) {
    List toRemove = new ArrayList();

    Iterator iter = fromList.iterator();
    while (iter.hasNext()) {
        PersistableBusinessObject copyLine = (PersistableBusinessObject) iter.next();

        PersistableBusinessObject line = (PersistableBusinessObject) PurApObjectUtils.retrieveObjectWithIdentitcalKey(controlList, copyLine);
        if (ObjectUtils.isNull(line)) {
            toRemove.add(copyLine);
        } else { // since we're not deleting try to recurse on this element
            processCollectionsRecurse(template, line, copyLine, depth);
        }
    }
    return toRemove;
}
 

import org.kuali.rice.krad.service.util.OjbCollectionAware; //导入依赖的package包/类
/**
 * This method processes collections recursively up to the depth level specified
 *
 * @param template
 * @param orig
 * @param copy
 */
private void processCollectionsRecurse(OjbCollectionAware template, PersistableBusinessObject orig, PersistableBusinessObject copy, int depth) {
    if (copy == null || depth < 1) {
        return;
    }

    List originalCollections = orig.buildListOfDeletionAwareLists();

    if (originalCollections != null && !originalCollections.isEmpty()) {
        /*
         * Prior to being saved, the version in the database will not yet reflect any deleted collections. So, a freshly
         * retrieved version will contain objects that need to be removed:
         */
        try {
            List copyCollections = copy.buildListOfDeletionAwareLists();
            int size = originalCollections.size();

            if (copyCollections.size() != size) {
                throw new RuntimeException("size mismatch while attempting to process list of Collections to manage");
            }

            for (int i = 0; i < size; i++) {
                Collection<PersistableBusinessObject> origSource = (Collection<PersistableBusinessObject>) originalCollections.get(i);
                Collection<PersistableBusinessObject> copySource = (Collection<PersistableBusinessObject>) copyCollections.get(i);
                List list = findUnwantedElements(copySource, origSource, template, depth - 1);
                cleanse(template, origSource, list);

            }
        } catch (ObjectRetrievalFailureException orfe) {
            // object wasn't found, must be pre-save
        }
    }
}
 

import org.kuali.rice.krad.service.util.OjbCollectionAware; //导入依赖的package包/类
/**
 * OJB RemovalAwareLists do not survive through the response/request lifecycle. This method is a work-around to forcibly remove
 * business objects that are found in Collections stored in the database but not in memory.
 *
 * @param orig
 * @param id
 * @param template
 */
public void processCollections2(OjbCollectionAware template, PersistableBusinessObject orig, PersistableBusinessObject copy) {
    // if copy is null this is the first time we are saving the object, don't have to worry about updating collections
    if (copy == null) {
        return;
    }

    List originalCollections = orig.buildListOfDeletionAwareLists();

    if (originalCollections != null && !originalCollections.isEmpty()) {
        /*
         * Prior to being saved, the version in the database will not yet reflect any deleted collections. So, a freshly
         * retrieved version will contain objects that need to be removed:
         */
        try {
            List copyCollections = copy.buildListOfDeletionAwareLists();
            int size = originalCollections.size();

            if (copyCollections.size() != size) {
                throw new RuntimeException("size mismatch while attempting to process list of Collections to manage");
            }

            for (int i = 0; i < size; i++) {
                Collection origSource = (Collection) originalCollections.get(i);
                Collection copySource = (Collection) copyCollections.get(i);
                List list = findUnwantedElements(copySource, origSource, null, 0);
                cleanse(template, origSource, list);

            }
        } catch (ObjectRetrievalFailureException orfe) {
            // object wasn't found, must be pre-save
        }
    }
}
 

import org.kuali.rice.krad.service.util.OjbCollectionAware; //导入依赖的package包/类
/**
 * This method deletes unwanted objects from the database as well as from the given input List
 *
 * @param origSource    - list containing unwanted business objects
 * @param unwantedItems - business objects to be permanently removed
 * @param template
 */
private void cleanse(OjbCollectionAware template, Collection origSource, List unwantedItems) {
    if (unwantedItems.size() > 0) {
        Iterator iter = unwantedItems.iterator();
        while (iter.hasNext()) {
            template.getPersistenceBrokerTemplate().delete(iter.next());
        }
    }

}
 

import org.kuali.rice.krad.service.util.OjbCollectionAware; //导入依赖的package包/类
/**
 * OJB RemovalAwareLists do not survive through the response/request lifecycle. This method is a work-around to forcibly remove
 * business objects that are found in Collections stored in the database but not in memory.
 *
 * @param orig
 * @param id
 * @param template
 */
public void processCollections(OjbCollectionAware template, PersistableBusinessObject orig, PersistableBusinessObject copy) {
    processCollectionsRecurse(template, orig, copy, MAX_DEPTH);
}