org.apache.jackrabbit.oak.util.AggregatingDescriptors Maven / Gradle / Ivy
/*
* 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.jackrabbit.oak.util;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import javax.jcr.Value;
import org.apache.jackrabbit.oak.api.Descriptors;
import org.apache.jackrabbit.oak.spi.whiteboard.Tracker;
/**
* An AggregatingDescriptors is an implementation of Descriptors
* that allows to aggregate multiple Descriptors (which are
* provided dynamically via a whiteboard tracker).
*/
public class AggregatingDescriptors implements Descriptors {
private final Tracker tracker;
/**
* Create an AggregatingDescriptors which uses descriptors.getServices()
* at method invocation time
*/
public AggregatingDescriptors(final Tracker tracker) {
if (tracker==null) {
throw new IllegalArgumentException("tracker must not be null");
}
this.tracker = tracker;
}
private List getDescriptors() {
final List descriptors = tracker.getServices();
if (descriptors==null) {
return Collections.emptyList();
} else {
return descriptors;
}
}
@Override
public String[] getKeys() {
Set keys = new HashSet();
for (Iterator it = getDescriptors().iterator(); it.hasNext();) {
Descriptors descriptors = it.next();
Collections.addAll(keys, descriptors.getKeys());
}
return keys.toArray(new String[keys.size()]);
}
@Override
public boolean isStandardDescriptor(@Nonnull String key) {
for (Iterator it = getDescriptors().iterator(); it.hasNext();) {
Descriptors descriptors = it.next();
if (descriptors.isStandardDescriptor(key)) {
return true;
}
}
return false;
}
@Override
public boolean isSingleValueDescriptor(@Nonnull String key) {
for (Iterator it = getDescriptors().iterator(); it.hasNext();) {
Descriptors descriptors = it.next();
if (descriptors.isSingleValueDescriptor(key)) {
return true;
}
}
return false;
}
@CheckForNull
@Override
public Value getValue(@Nonnull String key) {
for (Iterator it = getDescriptors().iterator(); it.hasNext();) {
Descriptors descriptors = it.next();
Value value = descriptors.getValue(key);
if (value!=null) {
return value;
}
}
return null;
}
@CheckForNull
@Override
public Value[] getValues(@Nonnull String key) {
for (Iterator it = getDescriptors().iterator(); it.hasNext();) {
Descriptors descriptors = it.next();
Value[] values = descriptors.getValues(key);
if (values!=null) {
return values;
}
}
return null;
}
}