/*******************************************************************************
* Copyright (c) 2013 Oracle. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* gonural - initial implementation
******************************************************************************/
package org.eclipse.persistence.jpa.rs.features.clientinitiated.paging;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.ws.rs.core.UriBuilder;
import javax.ws.rs.core.UriInfo;
import javax.xml.bind.JAXBElement;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.internal.jpa.rs.metadata.model.ItemLinks;
import org.eclipse.persistence.internal.jpa.rs.metadata.model.LinkV2;
import org.eclipse.persistence.internal.queries.ReportItem;
import org.eclipse.persistence.internal.weaving.PersistenceWeavedRest;
import org.eclipse.persistence.jpa.rs.PersistenceContext;
import org.eclipse.persistence.jpa.rs.QueryParameters;
import org.eclipse.persistence.jpa.rs.ReservedWords;
import org.eclipse.persistence.jpa.rs.features.FeatureResponseBuilderImpl;
import org.eclipse.persistence.jpa.rs.util.IdHelper;
import org.eclipse.persistence.jpa.rs.util.list.PageableCollection;
import org.eclipse.persistence.jpa.rs.util.list.ReadAllQueryResultCollection;
import org.eclipse.persistence.jpa.rs.util.list.ReportQueryResultCollection;
import org.eclipse.persistence.jpa.rs.util.list.ReportQueryResultListItem;
public class PagingResponseBuilder extends FeatureResponseBuilderImpl {
private static String NO_PREVIOUS_CHUNK = "-1";
/* (non-Javadoc)
* @see org.eclipse.persistence.jpa.rs.features.FeatureResponseBuilderImpl#buildReadAllQueryResponse(org.eclipse.persistence.jpa.rs.PersistenceContext, java.util.Map, java.util.List, javax.ws.rs.core.UriInfo)
*/
@Override
public Object buildReadAllQueryResponse(PersistenceContext context, Map<String, Object> queryParams, List<Object> items, UriInfo uriInfo) {
ReadAllQueryResultCollection response = new ReadAllQueryResultCollection();
for (Object item : items) {
response.addItem(populatePagedReadAllQueryItemLinks(context, item));
}
response.setCount(items.size());
return populatePagedCollectionLinks(queryParams, uriInfo, response);
}
/* (non-Javadoc)
* @see org.eclipse.persistence.jpa.rs.features.FeatureResponseBuilderImpl#buildReportQueryResponse(org.eclipse.persistence.jpa.rs.PersistenceContext, java.util.Map, java.util.List, java.util.List, javax.ws.rs.core.UriInfo)
*/
@Override
public Object buildReportQueryResponse(PersistenceContext context, Map<String, Object> queryParams, List<Object[]> results, List<ReportItem> items, UriInfo uriInfo) {
return populatePagedReportQueryCollectionLinks(queryParams, results, items, uriInfo);
}
/* (non-Javadoc)
* @see org.eclipse.persistence.jpa.rs.features.FeatureResponseBuilderImpl#buildAttributeResponse(org.eclipse.persistence.jpa.rs.PersistenceContext, java.util.Map, java.lang.String, java.lang.Object, javax.ws.rs.core.UriInfo)
*/
@Override
public Object buildAttributeResponse(PersistenceContext context, Map<String, Object> queryParams, String attribute, Object results, UriInfo uriInfo) {
if (results instanceof Collection) {
if (containsDomainObjects(results)) {
ReadAllQueryResultCollection collection = (ReadAllQueryResultCollection) results;
if (collection != null) {
List<Object> items = collection.getItems();
if ((items != null) && (!items.isEmpty())) {
ReadAllQueryResultCollection response = new ReadAllQueryResultCollection();
response.setItems(items);
response.setCount(collection.getItems().size());
return populatePagedCollectionLinks(queryParams, uriInfo, response);
}
}
}
}
return results;
}
@SuppressWarnings("rawtypes")
private boolean containsDomainObjects(Object object) {
Collection collection = (Collection) object;
for (Iterator iterator = collection.iterator(); iterator.hasNext();) {
Object collectionItem = iterator.next();
if (PersistenceWeavedRest.class.isAssignableFrom(collectionItem.getClass())) {
return true;
}
}
return false;
}
private Object populatePagedReadAllQueryItemLinks(PersistenceContext context, Object result) {
// populate links for the entity
ClassDescriptor descriptor = context.getJAXBDescriptorForClass(result.getClass());
if ((result instanceof PersistenceWeavedRest) && (descriptor != null) && (context != null)) {
ItemLinks itemLinks = new ItemLinks();
PersistenceWeavedRest entity = (PersistenceWeavedRest) result;
String entityId = IdHelper.stringifyId(result, descriptor.getAlias(), context);
String href = context.getBaseURI() + context.getVersion() + "/" + context.getName() + "/entity/" + descriptor.getAlias() + "/" + entityId;
itemLinks.addItem(new LinkV2(ReservedWords.JPARS_REL_SELF, href));
entity._persistence_setLinks(itemLinks);
return entity;
}
return result;
}
private PageableCollection populatePagedCollectionLinks(Map<String, Object> queryParams, UriInfo uriInfo, PageableCollection resultCollection) {
// populate links for entire response
List<LinkV2> links = new ArrayList<LinkV2>();
int limit = Integer.parseInt((String) queryParams.get(QueryParameters.JPARS_PAGING_LIMIT));
int offset = Integer.parseInt((String) queryParams.get(QueryParameters.JPARS_PAGING_OFFSET));
String nextOffset = null;
String prevOffset = null;
if (limit > offset) {
nextOffset = String.valueOf(limit);
prevOffset = NO_PREVIOUS_CHUNK;
} else {
if (limit == offset) {
prevOffset = "0";
}
nextOffset = String.valueOf(limit + offset);
prevOffset = String.valueOf(offset - limit);
}
UriBuilder uriBuilder;
if (resultCollection.getCount() != null) {
int actualCount = resultCollection.getCount();
if (actualCount >= limit) {
// next link
// The uri might have other query/matrix parameters, just replace the limit and offset
// for next and prev links and leave the rest untouched
uriBuilder = UriBuilder.fromUri(uriInfo.getRequestUri());
uriBuilder.replaceQueryParam(QueryParameters.JPARS_PAGING_OFFSET, nextOffset);
links.add(new LinkV2(ReservedWords.JPARS_REL_NEXT, uriBuilder.build().toString()));
resultCollection.setHasMore(true);
} else {
resultCollection.setHasMore(false);
}
}
if (!NO_PREVIOUS_CHUNK.equals(prevOffset)) {
// prev link
uriBuilder = UriBuilder.fromUri(uriInfo.getRequestUri());
uriBuilder.replaceQueryParam(QueryParameters.JPARS_PAGING_OFFSET, prevOffset);
links.add(new LinkV2(ReservedWords.JPARS_REL_PREV, uriBuilder.build().toString()));
}
links.add(new LinkV2(ReservedWords.JPARS_REL_SELF, uriInfo.getRequestUri().toString()));
resultCollection.setLinks(links);
resultCollection.setOffset(offset);
resultCollection.setLimit(limit);
return resultCollection;
}
/**
* Populate paged report query collection links.
*
* @param queryParams the query params
* @param results the results
* @param reportItems the report items
* @param uriInfo the uri info
* @return the pageable collection
*/
@SuppressWarnings({ "rawtypes" })
private PageableCollection populatePagedReportQueryCollectionLinks(Map<String, Object> queryParams, List<Object[]> results, List<ReportItem> reportItems, UriInfo uriInfo) {
ReportQueryResultCollection response = new ReportQueryResultCollection();
for (Object result : results) {
ReportQueryResultListItem queryResultListItem = new ReportQueryResultListItem();
List<JAXBElement> jaxbFields = createShellJAXBElementList(reportItems, result);
if (jaxbFields == null) {
return null;
}
// We don't have a way of determining self links for the report query responses
// so, no links array will be inserted into individual items in the response
queryResultListItem.setFields(jaxbFields);
response.addItem(queryResultListItem);
}
response.setCount(results.size());
return populatePagedCollectionLinks(queryParams, uriInfo, response);
}
}