001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017 package org.apache.logging.log4j.core.util; 018 019 import java.nio.charset.Charset; 020 021 import org.apache.logging.log4j.status.StatusLogger; 022 023 /** 024 * Charset utilities. Contains the standard character sets guaranteed to be available on all implementations of the 025 * Java platform. Parts adapted from JDK 1.7 (in particular, the {@code java.nio.charset.StandardCharsets} class). 026 * 027 * @see java.nio.charset.Charset 028 */ 029 public final class Charsets { 030 031 /** 032 * Seven-bit ASCII. ISO646-US. The Basic Latin block of the Unicode character set. 033 */ 034 public static final Charset US_ASCII = Charset.forName("US-ASCII"); 035 036 /** 037 * ISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1. 038 */ 039 public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1"); 040 041 /** 042 * Eight-bit UCS Transformation Format. 043 */ 044 public static final Charset UTF_8 = Charset.forName("UTF-8"); 045 046 /** 047 * Sixteen-bit UCS Transformation Format, big-endian byte order. 048 */ 049 public static final Charset UTF_16BE = Charset.forName("UTF-16BE"); 050 051 /** 052 * Sixteen-bit UCS Transformation Format, little-endian byte order. 053 */ 054 public static final Charset UTF_16LE = Charset.forName("UTF-16LE"); 055 056 /** 057 * Sixteen-bit UCS Transformation Format, byte order identified by an optional byte-order mark. 058 */ 059 public static final Charset UTF_16 = Charset.forName("UTF-16"); 060 061 /** 062 * Returns a Charset, if possible the Charset for the specified {@code charsetName}, otherwise (if the specified 063 * {@code charsetName} is {@code null} or not supported) this method returns the platform default Charset. 064 * 065 * @param charsetName 066 * name of the preferred charset or {@code null} 067 * @return a Charset, not null. 068 */ 069 public static Charset getSupportedCharset(final String charsetName) { 070 return getSupportedCharset(charsetName, Charset.defaultCharset()); 071 } 072 073 /** 074 * Returns a Charset, if possible the Charset for the specified {@code charsetName}, otherwise (if the specified 075 * {@code charsetName} is {@code null} or not supported) this method returns the platform default Charset. 076 * 077 * @param charsetName 078 * name of the preferred charset or {@code null} 079 * @param defaultCharset 080 * returned if {@code charsetName} is null or is not supported. 081 * @return a Charset, never null. 082 */ 083 public static Charset getSupportedCharset(final String charsetName, final Charset defaultCharset) { 084 Charset charset = null; 085 if (charsetName != null && Charset.isSupported(charsetName)) { 086 charset = Charset.forName(charsetName); 087 } 088 if (charset == null) { 089 charset = defaultCharset; 090 if (charsetName != null) { 091 StatusLogger.getLogger().error( 092 "Charset " + charsetName + " is not supported for layout, using " + charset.displayName()); 093 } 094 } 095 return charset; 096 } 097 098 private Charsets() { 099 } 100 101 }