com.mysema.query.group.GMap Maven / Gradle / Ivy
/*
* Copyright 2015, The Querydsl Team (http://www.querydsl.com/team)
*
* Licensed 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 com.mysema.query.group;
import java.util.*;
import com.mysema.commons.lang.Pair;
/**
* @param
* @param
*/
abstract class GMap> extends AbstractGroupExpression, M> {
private static final long serialVersionUID = 7106389414200843920L;
public GMap(QPair qpair) {
super(Map.class, qpair);
}
protected abstract M createMap();
@Override
public GroupCollector, M> createGroupCollector() {
return new GroupCollector, M>() {
private final M map = createMap();
@Override
public void add(Pair pair) {
map.put(pair.getFirst(), pair.getSecond());
}
@Override
public M get() {
return map;
}
};
}
public static GMap> createLinked(QPair expr) {
return new GMap>(expr) {
@Override
protected Map createMap() {
return new LinkedHashMap();
}
};
}
public static , U> GMap> createSorted(QPair expr) {
return new GMap>(expr) {
@Override
protected SortedMap createMap() {
return new TreeMap();
}
};
}
public static GMap> createSorted(QPair expr, final Comparator comparator) {
return new GMap>(expr) {
@Override
protected SortedMap createMap() {
return new TreeMap(comparator);
}
};
}
static class Mixin> extends AbstractGroupExpression, R> {
private static final long serialVersionUID = 1939989270493531116L;
private class GroupCollectorImpl implements GroupCollector, R> {
private final GroupCollector, R> groupCollector;
private final Map> keyCollectors = new LinkedHashMap>();
private final Map, GroupCollector> valueCollectors = new HashMap, GroupCollector>();
public GroupCollectorImpl() {
this.groupCollector = mixin.createGroupCollector();
}
@Override
public void add(Pair pair) {
K first = pair.getFirst();
GroupCollector keyCollector = keyCollectors.get(first);
if (keyCollector == null) {
keyCollector = keyExpression.createGroupCollector();
keyCollectors.put(first, keyCollector);
}
keyCollector.add(first);
GroupCollector valueCollector = valueCollectors.get(keyCollector);
if (valueCollector == null) {
valueCollector = valueExpression.createGroupCollector();
valueCollectors.put(keyCollector, valueCollector);
}
V second = pair.getSecond();
valueCollector.add(second);
}
@Override
public R get() {
for (GroupCollector keyCollector : keyCollectors.values()) {
T key = keyCollector.get();
GroupCollector valueCollector = valueCollectors.remove(keyCollector);
U value = valueCollector.get();
groupCollector.add(Pair.of(key, value));
}
keyCollectors.clear();
return groupCollector.get();
}
}
private final GroupExpression, R> mixin;
private final GroupExpression keyExpression;
private final GroupExpression valueExpression;
@SuppressWarnings({ "rawtypes", "unchecked" })
public Mixin(GroupExpression keyExpression, GroupExpression valueExpression, AbstractGroupExpression, R> mixin) {
super((Class) mixin.getType(), QPair.create(keyExpression.getExpression(), valueExpression.getExpression()));
this.keyExpression = keyExpression;
this.valueExpression = valueExpression;
this.mixin = mixin;
}
@Override
public GroupCollector, R> createGroupCollector() {
return new GroupCollectorImpl();
}
}
}