/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.sling.commons.json.sling;
import java.util.Iterator;
import java.util.LinkedList;
import org.apache.sling.api.request.RecursionTooDeepException;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.resource.ResourceUtil;
import org.apache.sling.commons.json.JSONException;
import org.apache.sling.commons.json.JSONObject;
public class ResourceTraversor {
public static final class Entry {
public final Resource resource;
public final JSONObject json;
public Entry(final Resource r, final JSONObject o) {
this.resource = r;
this.json = o;
}
}
private long count;
private long maxResources;
private final int maxRecursionLevels;
private final JSONObject startObject;
private LinkedList<Entry> currentQueue;
private LinkedList<Entry> nextQueue;
private final Resource startResource;
public ResourceTraversor(final int levels, final long maxResources, final Resource resource, final boolean tidy)
throws JSONException {
this.maxResources = maxResources;
this.maxRecursionLevels = levels;
this.startResource = resource;
currentQueue = new LinkedList<Entry>();
nextQueue = new LinkedList<Entry>();
this.startObject = this.adapt(resource);
}
/**
* Recursive descent from startResource, collecting JSONObjects into
* startObject. Throws a RecursionTooDeepException if the maximum number of
* nodes is reached on a "deep" traversal (where "deep" === level greater
* than 1).
*
* @return -1 if everything went fine, a positive valuew when the resource
* has more child nodes then allowed.
* @throws JSONException
*/
public int collectResources() throws RecursionTooDeepException, JSONException {
return collectChildren(startResource, this.startObject, 0);
}
/**
* @param resource
* @param currentLevel
* @throws JSONException
*/
private int collectChildren(final Resource resource,
final JSONObject jsonObj,
int currentLevel)
throws JSONException {
if (maxRecursionLevels == -1 || currentLevel < maxRecursionLevels) {
final Iterator<Resource> children = ResourceUtil.listChildren(resource);
while (children.hasNext()) {
count++;
final Resource res = children.next();
// SLING-2320: always allow enumeration of one's children;
// DOS-limitation is for deeper traversals.
if (count > maxResources && maxRecursionLevels != 1) {
return currentLevel;
}
final JSONObject json = collectResource(res, jsonObj);
nextQueue.addLast(new Entry(res, json));
}
}
while (!currentQueue.isEmpty() || !nextQueue.isEmpty()) {
if (currentQueue.isEmpty()) {
currentLevel++;
currentQueue = nextQueue;
nextQueue = new LinkedList<Entry>();
}
final Entry nextResource = currentQueue.removeFirst();
final int maxLevel = collectChildren(nextResource.resource, nextResource.json, currentLevel);
if ( maxLevel != -1 ) {
return maxLevel;
}
}
return -1;
}
/**
* Adds a resource in the JSON tree.
*
* @param resource The resource to add
* @param level The level where this resource is located.
* @throws JSONException
*/
private JSONObject collectResource(Resource resource, final JSONObject parent)
throws JSONException {
final JSONObject o = adapt(resource);
parent.put(ResourceUtil.getName(resource), o);
return o;
}
/**
* Adapt a Resource to a JSON Object.
*
* @param resource The resource to adapt.
* @return The JSON representation of the Resource
* @throws JSONException
*/
private JSONObject adapt(final Resource resource) throws JSONException {
return JsonObjectCreator.create(resource, 0);
}
/**
* @return The number of resources this visitor found.
*/
public long getCount() {
return count;
}
public JSONObject getJSONObject() {
return startObject;
}
}