/*
* 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 groovy.util;
import groovy.lang.Closure;
import org.codehaus.groovy.runtime.NumberAwareComparator;
import org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
/**
* A helper class for sorting objects via a closure to return the field
* or operation on which to sort.
*
* @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
*/
public class OrderBy<T> implements Comparator<T> {
private final List<Closure> closures;
private boolean equalityCheck;
private final NumberAwareComparator<Object> numberAwareComparator = new NumberAwareComparator<Object>();
public OrderBy() {
this(new ArrayList<Closure>(), false);
}
public OrderBy(boolean equalityCheck) {
this(new ArrayList<Closure>(), equalityCheck);
}
public OrderBy(Closure closure) {
this(closure, false);
}
public OrderBy(Closure closure, boolean equalityCheck) {
this(new ArrayList<Closure>(), equalityCheck);
closures.add(closure);
}
public OrderBy(List<Closure> closures) {
this(closures, false);
}
public OrderBy(List<Closure> closures, boolean equalityCheck) {
this.equalityCheck = equalityCheck;
this.closures = closures;
}
public void add(Closure closure) {
closures.add(closure);
}
public int compare(T object1, T object2) {
for (Closure closure : closures) {
Object value1 = closure.call(object1);
Object value2 = closure.call(object2);
int result;
if (!equalityCheck || (value1 instanceof Comparable && value2 instanceof Comparable)) {
result = numberAwareComparator.compare(value1, value2);
} else {
result = DefaultTypeTransformation.compareEqual(value1, value2) ? 0 : -1;
}
if (result == 0) continue;
return result;
}
return 0;
}
public boolean isEqualityCheck() {
return equalityCheck;
}
public void setEqualityCheck(boolean equalityCheck) {
this.equalityCheck = equalityCheck;
}
}