Java tutorial
//package com.java2s; /* * 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. */ import java.util.Locale; public class Main { /** * Same as toLocale(), but return null when it cannot derive a valid Locale object. * * @param str * @return */ public static Locale deriveLocale(String str) { if (str == null) { return null; } int len = str.length(); if (len != 2 && len != 5 && len < 7) { return null; } char ch0 = str.charAt(0); char ch1 = str.charAt(1); if (ch0 < 'a' || ch0 > 'z' || ch1 < 'a' || ch1 > 'z') { return null; } if (len == 2) { return new Locale(str, ""); } else { if (str.charAt(2) != '_') { return null; } char ch3 = str.charAt(3); if (ch3 == '_') { return new Locale(str.substring(0, 2), "", str.substring(4)); } char ch4 = str.charAt(4); if (ch3 < 'A' || ch3 > 'Z' || ch4 < 'A' || ch4 > 'Z') { return null; } if (len == 5) { return new Locale(str.substring(0, 2), str.substring(3, 5)); } else { if (str.charAt(5) != '_') { return null; } return new Locale(str.substring(0, 2), str.substring(3, 5), str.substring(6)); } } } }