Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright 2011-2013 HTTL 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.
 */

import java.util.Map;

public class Main {
    public static <K, V> void putIfAbsent(Map<K, V> from, Map<K, ? super V> to) {
        if (from == null || to == null) {
            return;
        }
        for (Map.Entry<K, V> entry : from.entrySet()) {
            if (!to.containsKey(entry.getKey())) {
                to.put(entry.getKey(), entry.getValue());
            }
        }
    }
}