Here you can find the source of format(Locale locale, String key, Object... arguments)
public static String format(Locale locale, String key, Object... arguments)
//package com.java2s; /**// w w w . j a va 2 s .c om * Copyright (c) 2017 Andrea Di Giorgi * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ import java.text.MessageFormat; import java.util.Locale; import java.util.ResourceBundle; public class Main { public static String format(Locale locale, String key, Object... arguments) { String pattern = get(locale, key); return MessageFormat.format(pattern, arguments); } public static String get(Locale locale, String key) { ResourceBundle resourceBundle = ResourceBundle.getBundle("content.Language", locale); return resourceBundle.getString(key); } }