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/*
* 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.dubbo.common.utils;
import java.lang.reflect.Method;
import java.util.Comparator;
/**
* The Comparator class for {@link Method}, the comparison rule :
*
* - Comparing to two {@link Method#getName() method names} {@link String#compareTo(String) lexicographically}.
* If equals, go to step 2
* - Comparing to the count of two method parameters. If equals, go to step 3
* - Comparing to the type names of methods parameter {@link String#compareTo(String) lexicographically}
*
*
* @since 2.7.6
*/
public class MethodComparator implements Comparator {
public static final MethodComparator INSTANCE = new MethodComparator();
private MethodComparator() {
}
@Override
public int compare(Method m1, Method m2) {
if (m1.equals(m2)) {
return 0;
}
// Step 1
String n1 = m1.getName();
String n2 = m2.getName();
int value = n1.compareTo(n2);
if (value == 0) { // Step 2
Class[] types1 = m1.getParameterTypes();
Class[] types2 = m2.getParameterTypes();
value = types1.length - types2.length;
if (value == 0) { // Step 3
for (int i = 0; i < types1.length; i++) {
value = types1[i].getName().compareTo(types2[i].getName());
if (value != 0) {
break;
}
}
}
}
return Integer.compare(value, 0);
}
}