Here you can find the source of load(final Properties props, final Properties toLoad)
public static final void load(final Properties props, final Properties toLoad) throws IOException
//package com.java2s; /*/*w w w. j a v a2 s. co m*/ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 2008 jOpenDocument, by ILM Informatique. All rights reserved. * * The contents of this file are subject to the terms of the GNU * General Public License Version 3 only ("GPL"). * You may not use this file except in compliance with the License. * You can obtain a copy of the License at http://www.gnu.org/licenses/gpl-3.0.html * See the License for the specific language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each file. * */ import java.io.IOException; import java.util.Properties; public class Main { public static final void load(final Properties props, final Properties toLoad) throws IOException { for (final String key : toLoad.stringPropertyNames()) { final String value = toLoad.getProperty(key); assert value != null; props.setProperty(key, value); } } }