| 1 | /* |
| 2 | * Copyright 2001-2005 Stephen Colebourne |
| 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 | package org.joda.time.tz; |
| 17 | |
| 18 | import java.io.DataInputStream; |
| 19 | import java.io.File; |
| 20 | import java.io.FileInputStream; |
| 21 | import java.io.IOException; |
| 22 | import java.io.InputStream; |
| 23 | import java.lang.ref.SoftReference; |
| 24 | import java.util.Map; |
| 25 | import java.util.Set; |
| 26 | import java.util.TreeMap; |
| 27 | import java.util.TreeSet; |
| 28 | |
| 29 | import org.joda.time.DateTimeZone; |
| 30 | |
| 31 | /** |
| 32 | * ZoneInfoProvider loads compiled data files as generated by |
| 33 | * {@link ZoneInfoCompiler}. |
| 34 | * <p> |
| 35 | * ZoneInfoProvider is thread-safe and publicly immutable. |
| 36 | * |
| 37 | * @author Brian S O'Neill |
| 38 | * @since 1.0 |
| 39 | */ |
| 40 | public class ZoneInfoProvider implements Provider { |
| 41 | |
| 42 | /** The directory where the files are held. */ |
| 43 | private final File iFileDir; |
| 44 | /** The resource path. */ |
| 45 | private final String iResourcePath; |
| 46 | /** The class loader to use. */ |
| 47 | private final ClassLoader iLoader; |
| 48 | /** Maps ids to strings or SoftReferences to DateTimeZones. */ |
| 49 | private final Map iZoneInfoMap; |
| 50 | |
| 51 | /** |
| 52 | * ZoneInfoProvider searches the given directory for compiled data files. |
| 53 | * |
| 54 | * @throws IOException if directory or map file cannot be read |
| 55 | */ |
| 56 | public ZoneInfoProvider(File fileDir) throws IOException { |
| 57 | if (fileDir == null) { |
| 58 | throw new IllegalArgumentException("No file directory provided"); |
| 59 | } |
| 60 | if (!fileDir.exists()) { |
| 61 | throw new IOException("File directory doesn't exist: " + fileDir); |
| 62 | } |
| 63 | if (!fileDir.isDirectory()) { |
| 64 | throw new IOException("File doesn't refer to a directory: " + fileDir); |
| 65 | } |
| 66 | |
| 67 | iFileDir = fileDir; |
| 68 | iResourcePath = null; |
| 69 | iLoader = null; |
| 70 | |
| 71 | iZoneInfoMap = loadZoneInfoMap(openResource("ZoneInfoMap")); |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * ZoneInfoProvider searches the given ClassLoader resource path for |
| 76 | * compiled data files. Resources are loaded from the ClassLoader that |
| 77 | * loaded this class. |
| 78 | * |
| 79 | * @throws IOException if directory or map file cannot be read |
| 80 | */ |
| 81 | public ZoneInfoProvider(String resourcePath) throws IOException { |
| 82 | this(resourcePath, null, false); |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * ZoneInfoProvider searches the given ClassLoader resource path for |
| 87 | * compiled data files. |
| 88 | * |
| 89 | * @param loader ClassLoader to load compiled data files from. If null, |
| 90 | * use system ClassLoader. |
| 91 | * @throws IOException if directory or map file cannot be read |
| 92 | */ |
| 93 | public ZoneInfoProvider(String resourcePath, ClassLoader loader) |
| 94 | throws IOException |
| 95 | { |
| 96 | this(resourcePath, loader, true); |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * @param favorSystemLoader when true, use the system class loader if |
| 101 | * loader null. When false, use the current class loader if loader is null. |
| 102 | */ |
| 103 | private ZoneInfoProvider(String resourcePath, |
| 104 | ClassLoader loader, boolean favorSystemLoader) |
| 105 | throws IOException |
| 106 | { |
| 107 | if (resourcePath == null) { |
| 108 | throw new IllegalArgumentException("No resource path provided"); |
| 109 | } |
| 110 | if (!resourcePath.endsWith("/")) { |
| 111 | resourcePath += '/'; |
| 112 | } |
| 113 | |
| 114 | iFileDir = null; |
| 115 | iResourcePath = resourcePath; |
| 116 | |
| 117 | if (loader == null && !favorSystemLoader) { |
| 118 | loader = getClass().getClassLoader(); |
| 119 | } |
| 120 | |
| 121 | iLoader = loader; |
| 122 | |
| 123 | iZoneInfoMap = loadZoneInfoMap(openResource("ZoneInfoMap")); |
| 124 | } |
| 125 | |
| 126 | //----------------------------------------------------------------------- |
| 127 | /** |
| 128 | * If an error is thrown while loading zone data, uncaughtException is |
| 129 | * called to log the error and null is returned for this and all future |
| 130 | * requests. |
| 131 | * |
| 132 | * @param id the id to load |
| 133 | * @return the loaded zone |
| 134 | */ |
| 135 | public synchronized DateTimeZone getZone(String id) { |
| 136 | if (id == null) { |
| 137 | return null; |
| 138 | } |
| 139 | |
| 140 | Object obj = iZoneInfoMap.get(id); |
| 141 | if (obj == null) { |
| 142 | return null; |
| 143 | } |
| 144 | |
| 145 | if (id.equals(obj)) { |
| 146 | // Load zone data for the first time. |
| 147 | return loadZoneData(id); |
| 148 | } |
| 149 | |
| 150 | if (obj instanceof SoftReference) { |
| 151 | DateTimeZone tz = (DateTimeZone)((SoftReference)obj).get(); |
| 152 | if (tz != null) { |
| 153 | return tz; |
| 154 | } |
| 155 | // Reference cleared; load data again. |
| 156 | return loadZoneData(id); |
| 157 | } |
| 158 | |
| 159 | // If this point is reached, mapping must link to another. |
| 160 | return getZone((String)obj); |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * Gets a list of all the available zone ids. |
| 165 | * |
| 166 | * @return the zone ids |
| 167 | */ |
| 168 | public synchronized Set getAvailableIDs() { |
| 169 | // Return a copy of the keys rather than an umodifiable collection. |
| 170 | // This prevents ConcurrentModificationExceptions from being thrown by |
| 171 | // some JVMs if zones are opened while this set is iterated over. |
| 172 | return new TreeSet(iZoneInfoMap.keySet()); |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * Called if an exception is thrown from getZone while loading zone data. |
| 177 | * |
| 178 | * @param ex the exception |
| 179 | */ |
| 180 | protected void uncaughtException(Exception ex) { |
| 181 | Thread t = Thread.currentThread(); |
| 182 | t.getThreadGroup().uncaughtException(t, ex); |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * Opens a resource from file or classpath. |
| 187 | * |
| 188 | * @param name the name to open |
| 189 | * @return the input stream |
| 190 | * @throws IOException if an error occurs |
| 191 | */ |
| 192 | private InputStream openResource(String name) throws IOException { |
| 193 | InputStream in; |
| 194 | if (iFileDir != null) { |
| 195 | in = new FileInputStream(new File(iFileDir, name)); |
| 196 | } else { |
| 197 | String path = iResourcePath.concat(name); |
| 198 | if (iLoader != null) { |
| 199 | in = iLoader.getResourceAsStream(path); |
| 200 | } else { |
| 201 | in = ClassLoader.getSystemResourceAsStream(path); |
| 202 | } |
| 203 | if (in == null) { |
| 204 | StringBuffer buf = new StringBuffer(40) |
| 205 | .append("Resource not found: \"") |
| 206 | .append(path) |
| 207 | .append("\" ClassLoader: ") |
| 208 | .append(iLoader != null ? iLoader.toString() : "system"); |
| 209 | throw new IOException(buf.toString()); |
| 210 | } |
| 211 | } |
| 212 | return in; |
| 213 | } |
| 214 | |
| 215 | /** |
| 216 | * Loads the time zone data for one id. |
| 217 | * |
| 218 | * @param id the id to load |
| 219 | * @return the zone |
| 220 | */ |
| 221 | private DateTimeZone loadZoneData(String id) { |
| 222 | InputStream in = null; |
| 223 | try { |
| 224 | in = openResource(id); |
| 225 | DateTimeZone tz = DateTimeZoneBuilder.readFrom(in, id); |
| 226 | iZoneInfoMap.put(id, new SoftReference(tz)); |
| 227 | return tz; |
| 228 | } catch (IOException e) { |
| 229 | uncaughtException(e); |
| 230 | iZoneInfoMap.remove(id); |
| 231 | return null; |
| 232 | } finally { |
| 233 | try { |
| 234 | if (in != null) { |
| 235 | in.close(); |
| 236 | } |
| 237 | } catch (IOException e) { |
| 238 | } |
| 239 | } |
| 240 | } |
| 241 | |
| 242 | //----------------------------------------------------------------------- |
| 243 | /** |
| 244 | * Loads the zone info map. |
| 245 | * |
| 246 | * @param in the input stream |
| 247 | * @return the map |
| 248 | */ |
| 249 | private static Map loadZoneInfoMap(InputStream in) throws IOException { |
| 250 | Map map = new TreeMap(String.CASE_INSENSITIVE_ORDER); |
| 251 | DataInputStream din = new DataInputStream(in); |
| 252 | try { |
| 253 | readZoneInfoMap(din, map); |
| 254 | } finally { |
| 255 | try { |
| 256 | din.close(); |
| 257 | } catch (IOException e) { |
| 258 | } |
| 259 | } |
| 260 | map.put("UTC", new SoftReference(DateTimeZone.UTC)); |
| 261 | return map; |
| 262 | } |
| 263 | |
| 264 | /** |
| 265 | * Reads the zone info map from file. |
| 266 | * |
| 267 | * @param din the input stream |
| 268 | * @param zimap gets filled with string id to string id mappings |
| 269 | */ |
| 270 | private static void readZoneInfoMap(DataInputStream din, Map zimap) throws IOException { |
| 271 | // Read the string pool. |
| 272 | int size = din.readUnsignedShort(); |
| 273 | String[] pool = new String[size]; |
| 274 | for (int i=0; i<size; i++) { |
| 275 | pool[i] = din.readUTF().intern(); |
| 276 | } |
| 277 | |
| 278 | // Read the mappings. |
| 279 | size = din.readUnsignedShort(); |
| 280 | for (int i=0; i<size; i++) { |
| 281 | try { |
| 282 | zimap.put(pool[din.readUnsignedShort()], pool[din.readUnsignedShort()]); |
| 283 | } catch (ArrayIndexOutOfBoundsException e) { |
| 284 | throw new IOException("Corrupt zone info map"); |
| 285 | } |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | } |