Java tutorial
//package com.java2s; /* * Copyright 2002-2014 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.Locale; public class Main { /** * Determine the RFC 3066 compliant language tag, * as used for the HTTP "Accept-Language" header. * @param locale the Locale to transform to a language tag * @return the RFC 3066 compliant language tag as String */ public static String toLanguageTag(Locale locale) { return locale.getLanguage() + (hasText(locale.getCountry()) ? "-" + locale.getCountry() : ""); } /** * Check whether the given CharSequence has actual text. * More specifically, returns {@code true} if the string not {@code null}, * its length is greater than 0, and it contains at least one non-whitespace character. * <p><pre class="code"> * StringUtils.hasText(null) = false * StringUtils.hasText("") = false * StringUtils.hasText(" ") = false * StringUtils.hasText("12345") = true * StringUtils.hasText(" 12345 ") = true * </pre> * @param str the CharSequence to check (may be {@code null}) * @return {@code true} if the CharSequence is not {@code null}, * its length is greater than 0, and it does not contain whitespace only * @see Character#isWhitespace */ public static boolean hasText(CharSequence str) { if (!hasLength(str)) { return false; } int strLen = str.length(); for (int i = 0; i < strLen; i++) { if (!Character.isWhitespace(str.charAt(i))) { return true; } } return false; } /** * Check whether the given String has actual text. * More specifically, returns {@code true} if the string not {@code null}, * its length is greater than 0, and it contains at least one non-whitespace character. * @param str the String to check (may be {@code null}) * @return {@code true} if the String is not {@code null}, its length is * greater than 0, and it does not contain whitespace only * @see #hasText(CharSequence) */ public static boolean hasText(String str) { return hasText((CharSequence) str); } /** * Check that the given CharSequence is neither {@code null} nor of length 0. * Note: Will return {@code true} for a CharSequence that purely consists of whitespace. * <p><pre class="code"> * StringUtils.hasLength(null) = false * StringUtils.hasLength("") = false * StringUtils.hasLength(" ") = true * StringUtils.hasLength("Hello") = true * </pre> * @param str the CharSequence to check (may be {@code null}) * @return {@code true} if the CharSequence is not null and has length * @see #hasText(String) */ public static boolean hasLength(CharSequence str) { return (str != null && str.length() > 0); } /** * Check that the given String is neither {@code null} nor of length 0. * Note: Will return {@code true} for a String that purely consists of whitespace. * @param str the String to check (may be {@code null}) * @return {@code true} if the String is not null and has length * @see #hasLength(CharSequence) */ public static boolean hasLength(String str) { return hasLength((CharSequence) str); } }