1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache license, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the license for the specific language governing permissions and 15 * limitations under the license. 16 */ 17 package org.apache.logging.log4j.core.util; 18 19 import java.nio.charset.Charset; 20 21 import org.apache.logging.log4j.status.StatusLogger; 22 23 /** 24 * Charset utilities. Contains the standard character sets guaranteed to be available on all implementations of the 25 * Java platform. Parts adapted from JDK 1.7 (in particular, the {@code java.nio.charset.StandardCharsets} class). 26 * 27 * @see java.nio.charset.Charset 28 */ 29 public final class Charsets { 30 31 /** 32 * Seven-bit ASCII. ISO646-US. The Basic Latin block of the Unicode character set. 33 */ 34 public static final Charset US_ASCII = Charset.forName("US-ASCII"); 35 36 /** 37 * ISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1. 38 */ 39 public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1"); 40 41 /** 42 * Eight-bit UCS Transformation Format. 43 */ 44 public static final Charset UTF_8 = Charset.forName("UTF-8"); 45 46 /** 47 * Sixteen-bit UCS Transformation Format, big-endian byte order. 48 */ 49 public static final Charset UTF_16BE = Charset.forName("UTF-16BE"); 50 51 /** 52 * Sixteen-bit UCS Transformation Format, little-endian byte order. 53 */ 54 public static final Charset UTF_16LE = Charset.forName("UTF-16LE"); 55 56 /** 57 * Sixteen-bit UCS Transformation Format, byte order identified by an optional byte-order mark. 58 */ 59 public static final Charset UTF_16 = Charset.forName("UTF-16"); 60 61 /** 62 * Returns a Charset, if possible the Charset for the specified {@code charsetName}, otherwise (if the specified 63 * {@code charsetName} is {@code null} or not supported) this method returns the platform default Charset. 64 * 65 * @param charsetName 66 * name of the preferred charset or {@code null} 67 * @return a Charset, not null. 68 */ 69 public static Charset getSupportedCharset(final String charsetName) { 70 return getSupportedCharset(charsetName, Charset.defaultCharset()); 71 } 72 73 /** 74 * Returns a Charset, if possible the Charset for the specified {@code charsetName}, otherwise (if the specified 75 * {@code charsetName} is {@code null} or not supported) this method returns the platform default Charset. 76 * 77 * @param charsetName 78 * name of the preferred charset or {@code null} 79 * @param defaultCharset 80 * returned if {@code charsetName} is null or is not supported. 81 * @return a Charset, never null. 82 */ 83 public static Charset getSupportedCharset(final String charsetName, final Charset defaultCharset) { 84 Charset charset = null; 85 if (charsetName != null && Charset.isSupported(charsetName)) { 86 charset = Charset.forName(charsetName); 87 } 88 if (charset == null) { 89 charset = defaultCharset; 90 if (charsetName != null) { 91 StatusLogger.getLogger().error( 92 "Charset " + charsetName + " is not supported for layout, using " + charset.displayName()); 93 } 94 } 95 return charset; 96 } 97 98 private Charsets() { 99 } 100 101 }