1 /* 2 * Copyright (C) 2012 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package java.nio.charset; 18 19 import java.util.Collections; 20 import java.util.SortedMap; 21 import java.util.TreeMap; 22 23 /** 24 * A minimal GWT emulation of {@link Charset}. 25 * 26 * @author Gregory Kick 27 */ 28 public abstract class Charset implements Comparable<Charset> { 29 private static final Charset UTF_8 = new Charset("UTF-8") {}; 30 31 private static final SortedMap<String, Charset> AVAILABLE_CHARSETS = 32 new TreeMap<String, Charset>(); 33 static { 34 AVAILABLE_CHARSETS.put(UTF_8.name(), UTF_8); 35 } 36 37 public static SortedMap<String, Charset> availableCharsets() { 38 return Collections.unmodifiableSortedMap(AVAILABLE_CHARSETS); 39 } 40 41 public static Charset forName(String charsetName) { 42 if (charsetName == null) { 43 throw new IllegalArgumentException("Null charset name"); 44 } 45 int length = charsetName.length(); 46 if (length == 0) { 47 throw new IllegalCharsetNameException(charsetName); 48 } 49 for (int i = 0; i < length; i++) { 50 char c = charsetName.charAt(i); 51 if ((c >= 'A' && c <= 'Z') 52 || (c >= 'a' && c <= 'z') 53 || (c >= '0' && c <= '9') 54 || (c == '-' && i != 0) 55 || (c == ':' && i != 0) 56 || (c == '_' && i != 0) 57 || (c == '.' && i != 0)) { 58 continue; 59 } 60 throw new IllegalCharsetNameException(charsetName); 61 } 62 Charset charset = AVAILABLE_CHARSETS.get(charsetName.toUpperCase()); 63 if (charset != null) { 64 return charset; 65 } 66 throw new UnsupportedCharsetException(charsetName); 67 } 68 69 private final String name; 70 71 private Charset(String name) { 72 this.name = name; 73 } 74 75 public final String name() { 76 return name; 77 } 78 79 public final int compareTo(Charset that) { 80 return this.name.compareToIgnoreCase(that.name); 81 } 82 83 public final int hashCode() { 84 return name.hashCode(); 85 } 86 87 public final boolean equals(Object o) { 88 if (o == this) { 89 return true; 90 } else if (o instanceof Charset) { 91 Charset that = (Charset) o; 92 return this.name.equals(that.name); 93 } else { 94 return false; 95 } 96 } 97 98 public final String toString() { 99 return name; 100 } 101 } 102
