1 /* |
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2 * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 package sun.io; |
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27 |
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28 import java.io.UnsupportedEncodingException; |
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29 import java.lang.ref.SoftReference; |
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30 import java.util.Properties; |
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31 |
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32 /** |
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33 * Package-private utility class that caches the default converter classes and |
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34 * provides other logic common to both the ByteToCharConverter and |
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35 * CharToByteConverter classes. |
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36 * |
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37 * @author Mark Reinhold |
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38 * @since 1.2 |
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39 * |
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40 * @deprecated Replaced by {@link java.nio.charset}. THIS API WILL BE |
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41 * REMOVED IN J2SE 1.6. |
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42 */ |
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43 @Deprecated |
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44 public class Converters { |
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45 |
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46 private Converters() { } /* To prevent instantiation */ |
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47 |
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48 /* Lock for all static fields in this class */ |
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49 private static Object lock = Converters.class; |
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50 |
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51 /* Cached values of system properties */ |
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52 private static String converterPackageName = null; /* file.encoding.pkg */ |
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53 private static String defaultEncoding = null; /* file.encoding */ |
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54 |
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55 /* Converter type constants and names */ |
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56 public static final int BYTE_TO_CHAR = 0; |
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57 public static final int CHAR_TO_BYTE = 1; |
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58 private static final String[] converterPrefix = { "ByteToChar", |
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59 "CharToByte" }; |
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60 |
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61 |
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62 // -- Converter class cache -- |
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63 |
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64 private static final int CACHE_SIZE = 3; |
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65 |
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66 /* For the default charset, whatever it turns out to be */ |
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67 private static final Object DEFAULT_NAME = new Object(); |
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68 |
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69 /* Cached converter classes, CACHE_SIZE per converter type. Each cache |
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70 * entry is a soft reference to a two-object array; the first element of |
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71 * the array is the converter class, the second is an object (typically a |
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72 * string) representing the encoding name that was used to request the |
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73 * converter, e.g., |
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74 * |
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75 * ((Object[])classCache[CHAR_TO_BYTE][i].get())[0] |
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76 * |
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77 * will be a CharToByteConverter and |
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78 * |
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79 * ((Object[])classCache[CHAR_TO_BYTE][i].get())[1] |
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80 * |
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81 * will be the string encoding name used to request it, assuming that cache |
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82 * entry i is valid. |
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83 * |
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84 * Ordinarily we'd do this with a private static utility class, but since |
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85 * this code can be involved in the startup sequence it's important to keep |
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86 * the footprint down. |
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87 */ |
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88 @SuppressWarnings("unchecked") |
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89 private static SoftReference<Object[]>[][] classCache |
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90 = (SoftReference<Object[]>[][]) new SoftReference<?>[][] { |
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91 new SoftReference<?>[CACHE_SIZE], |
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92 new SoftReference<?>[CACHE_SIZE] |
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93 }; |
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94 |
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95 private static void moveToFront(Object[] oa, int i) { |
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96 Object ob = oa[i]; |
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97 for (int j = i; j > 0; j--) |
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98 oa[j] = oa[j - 1]; |
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99 oa[0] = ob; |
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100 } |
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101 |
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102 private static Class<?> cache(int type, Object encoding) { |
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103 SoftReference<Object[]>[] srs = classCache[type]; |
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104 for (int i = 0; i < CACHE_SIZE; i++) { |
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105 SoftReference<Object[]> sr = srs[i]; |
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106 if (sr == null) |
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107 continue; |
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108 Object[] oa = sr.get(); |
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109 if (oa == null) { |
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110 srs[i] = null; |
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111 continue; |
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112 } |
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113 if (oa[1].equals(encoding)) { |
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114 moveToFront(srs, i); |
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115 return (Class<?>)oa[0]; |
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116 } |
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117 } |
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118 return null; |
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119 } |
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120 |
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121 private static Class<?> cache(int type, Object encoding, Class<?> c) { |
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122 SoftReference<Object[]>[] srs = classCache[type]; |
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123 srs[CACHE_SIZE - 1] = new SoftReference<>(new Object[] { c, encoding }); |
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124 moveToFront(srs, CACHE_SIZE - 1); |
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125 return c; |
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126 } |
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127 |
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128 /* Used to avoid doing expensive charset lookups for charsets that are not |
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129 * yet directly supported by NIO. |
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130 */ |
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131 public static boolean isCached(int type, String encoding) { |
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132 synchronized (lock) { |
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133 SoftReference<Object[]>[] srs = classCache[type]; |
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134 for (int i = 0; i < CACHE_SIZE; i++) { |
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135 SoftReference<Object[]> sr = srs[i]; |
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136 if (sr == null) |
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137 continue; |
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138 Object[] oa = sr.get(); |
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139 if (oa == null) { |
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140 srs[i] = null; |
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141 continue; |
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142 } |
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143 if (oa[1].equals(encoding)) |
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144 return true; |
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145 } |
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146 return false; |
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147 } |
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148 } |
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149 |
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150 |
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151 |
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152 /** Get the name of the converter package */ |
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153 private static String getConverterPackageName() { |
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154 String cp = converterPackageName; |
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155 if (cp != null) return cp; |
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156 java.security.PrivilegedAction<String> pa = |
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157 new sun.security.action.GetPropertyAction("file.encoding.pkg"); |
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158 cp = java.security.AccessController.doPrivileged(pa); |
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159 if (cp != null) { |
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160 /* Property is set, so take it as the true converter package */ |
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161 converterPackageName = cp; |
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162 } else { |
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163 /* Fall back to sun.io */ |
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164 cp = "sun.io"; |
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165 } |
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166 return cp; |
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167 } |
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168 |
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169 public static String getDefaultEncodingName() { |
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170 synchronized (lock) { |
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171 if (defaultEncoding == null) { |
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172 java.security.PrivilegedAction<String> pa = |
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173 new sun.security.action.GetPropertyAction("file.encoding"); |
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174 defaultEncoding = java.security.AccessController.doPrivileged(pa); |
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175 } |
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176 } |
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177 return defaultEncoding; |
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178 } |
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179 |
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180 public static void resetDefaultEncodingName() { |
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181 // This method should only be called during VM initialization. |
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182 if (sun.misc.VM.isBooted()) |
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183 return; |
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184 |
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185 synchronized (lock) { |
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186 defaultEncoding = "ISO-8859-1"; |
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187 Properties p = System.getProperties(); |
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188 p.setProperty("file.encoding", defaultEncoding); |
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189 System.setProperties(p); |
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190 } |
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191 } |
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192 |
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193 /** |
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194 * Get the class that implements the given type of converter for the named |
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195 * encoding, or throw an UnsupportedEncodingException if no such class can |
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196 * be found |
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197 */ |
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198 private static Class<?> getConverterClass(int type, String encoding) |
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199 throws UnsupportedEncodingException |
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200 { |
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201 String enc = null; |
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202 |
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203 /* "ISO8859_1" is the canonical name for the ISO-Latin-1 encoding. |
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204 Native code in the JDK commonly uses the alias "8859_1" instead of |
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205 "ISO8859_1". We hardwire this alias here in order to avoid loading |
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206 the full alias table just for this case. */ |
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207 if (!encoding.equals("ISO8859_1")) { |
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208 if (encoding.equals("8859_1")) { |
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209 enc = "ISO8859_1"; |
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210 /* |
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211 * On Solaris with nl_langinfo() called in GetJavaProperties(): |
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212 * |
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213 * locale undefined -> NULL -> hardcoded default |
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214 * "C" locale -> "" -> hardcoded default (on 2.6) |
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215 * "C" locale -> "646" (on 2.7) |
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216 * "en_US" locale -> "ISO8859-1" |
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217 * "en_GB" locale -> "ISO8859-1" (on 2.7) |
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218 * "en_UK" locale -> "ISO8859-1" (on 2.6) |
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219 */ |
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220 } else if (encoding.equals("ISO8859-1")) { |
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221 enc = "ISO8859_1"; |
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222 } else if (encoding.equals("646")) { |
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223 enc = "ASCII"; |
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224 } else { |
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225 enc = CharacterEncoding.aliasName(encoding); |
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226 } |
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227 } |
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228 if (enc == null) { |
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229 enc = encoding; |
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230 } |
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231 |
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232 try { |
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233 return Class.forName(getConverterPackageName() |
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234 + "." + converterPrefix[type] + enc); |
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235 } catch(ClassNotFoundException e) { |
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236 throw new UnsupportedEncodingException(enc); |
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237 } |
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238 |
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239 } |
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240 |
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241 /** |
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242 * Instantiate the given converter class, or throw an |
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243 * UnsupportedEncodingException if it cannot be instantiated |
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244 */ |
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245 private static Object newConverter(String enc, Class<?> c) |
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246 throws UnsupportedEncodingException |
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247 { |
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248 try { |
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249 return c.newInstance(); |
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250 } catch(InstantiationException e) { |
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251 throw new UnsupportedEncodingException(enc); |
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252 } catch(IllegalAccessException e) { |
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253 throw new UnsupportedEncodingException(enc); |
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254 } |
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255 } |
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256 |
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257 /** |
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258 * Create a converter object that implements the given type of converter |
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259 * for the given encoding, or throw an UnsupportedEncodingException if no |
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260 * appropriate converter class can be found and instantiated |
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261 */ |
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262 static Object newConverter(int type, String enc) |
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263 throws UnsupportedEncodingException |
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264 { |
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265 Class<?> c; |
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266 synchronized (lock) { |
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267 c = cache(type, enc); |
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268 if (c == null) { |
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269 c = getConverterClass(type, enc); |
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270 if (!c.getName().equals("sun.io.CharToByteUTF8")) |
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271 cache(type, enc, c); |
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272 } |
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273 } |
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274 return newConverter(enc, c); |
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275 } |
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276 |
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277 /** |
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278 * Find the class that implements the given type of converter for the |
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279 * default encoding. If the default encoding cannot be determined or is |
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280 * not yet defined, return a class that implements the fallback default |
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281 * encoding, which is just ISO 8859-1. |
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282 */ |
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283 private static Class<?> getDefaultConverterClass(int type) { |
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284 boolean fillCache = false; |
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285 Class<?> c; |
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286 |
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287 /* First check the class cache */ |
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288 c = cache(type, DEFAULT_NAME); |
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289 if (c != null) |
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290 return c; |
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291 |
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292 /* Determine the encoding name */ |
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293 String enc = getDefaultEncodingName(); |
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294 if (enc != null) { |
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295 /* file.encoding has been set, so cache the converter class */ |
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296 fillCache = true; |
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297 } else { |
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298 /* file.encoding has not been set, so use a default encoding which |
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299 will not be cached */ |
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300 enc = "ISO8859_1"; |
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301 } |
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302 |
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303 /* We have an encoding name; try to find its class */ |
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304 try { |
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305 c = getConverterClass(type, enc); |
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306 if (fillCache) { |
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307 cache(type, DEFAULT_NAME, c); |
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308 } |
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309 } catch (UnsupportedEncodingException x) { |
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310 /* Can't find the default class, so fall back to ISO 8859-1 */ |
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311 try { |
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312 c = getConverterClass(type, "ISO8859_1"); |
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313 } catch (UnsupportedEncodingException y) { |
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314 throw new InternalError("Cannot find default " |
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315 + converterPrefix[type] |
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316 + " converter class"); |
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317 } |
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318 } |
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319 return c; |
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320 |
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321 } |
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322 |
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323 /** |
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324 * Create a converter object that implements the given type of converter |
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325 * for the default encoding, falling back to ISO 8859-1 if the default |
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326 * encoding cannot be determined. |
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327 */ |
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328 static Object newDefaultConverter(int type) { |
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329 Class<?> c; |
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330 synchronized (lock) { |
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331 c = getDefaultConverterClass(type); |
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332 } |
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333 try { |
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334 return newConverter("", c); |
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335 } catch (UnsupportedEncodingException x) { |
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336 throw new InternalError("Cannot instantiate default converter" |
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337 + " class " + c.getName()); |
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338 } |
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339 } |
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340 |
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341 } |
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