Java tutorial
//package com.java2s; /* * Copyright 2002-2016 the original author or authors. * * 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.Enumeration; import java.util.Map; import java.util.Properties; public class Main { /** * Merge the given Properties instance into the given Map, * copying all properties (key-value pairs) over. * <p>Uses {@code Properties.propertyNames()} to even catch * default properties linked into the original Properties instance. * @param props the Properties instance to merge (may be {@code null}) * @param map the target Map to merge the properties into */ @SuppressWarnings("unchecked") public static <K, V> void mergePropertiesIntoMap(Properties props, Map<K, V> map) { if (map == null) { throw new IllegalArgumentException("Map must not be null"); } if (props != null) { for (Enumeration<?> en = props.propertyNames(); en.hasMoreElements();) { String key = (String) en.nextElement(); Object value = props.get(key); if (value == null) { // Allow for defaults fallback or potentially overridden accessor... value = props.getProperty(key); } map.put((K) key, (V) value); } } } }