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| 1 | +/* | |
| 2 | + * Copyright (c) 2000, 2006, Oracle and/or its affiliates. All rights reserved. | |
| 3 | + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 | + * | |
| 5 | + * This code is free software; you can redistribute it and/or modify it | |
| 6 | + * under the terms of the GNU General Public License version 2 only, as | |
| 7 | + * published by the Free Software Foundation. Oracle designates this | |
| 8 | + * particular file as subject to the "Classpath" exception as provided | |
| 9 | + * by Oracle in the LICENSE file that accompanied this code. | |
| 10 | + * | |
| 11 | + * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 12 | + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 | + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 | + * version 2 for more details (a copy is included in the LICENSE file that | |
| 15 | + * accompanied this code). | |
| 16 | + * | |
| 17 | + * You should have received a copy of the GNU General Public License version | |
| 18 | + * 2 along with this work; if not, write to the Free Software Foundation, | |
| 19 | + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 20 | + * | |
| 21 | + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| 22 | + * or visit www.oracle.com if you need additional information or have any | |
| 23 | + * questions. | |
| 24 | + */ | |
| 25 | + | |
| 26 | + | |
| 27 | +package java.util.logging; | |
| 28 | + | |
| 29 | +import java.io.UnsupportedEncodingException; | |
| 30 | +/** | |
| 31 | + * A <tt>Handler</tt> object takes log messages from a <tt>Logger</tt> and | |
| 32 | + * exports them. It might for example, write them to a console | |
| 33 | + * or write them to a file, or send them to a network logging service, | |
| 34 | + * or forward them to an OS log, or whatever. | |
| 35 | + * <p> | |
| 36 | + * A <tt>Handler</tt> can be disabled by doing a <tt>setLevel(Level.OFF)</tt> | |
| 37 | + * and can be re-enabled by doing a <tt>setLevel</tt> with an appropriate level. | |
| 38 | + * <p> | |
| 39 | + * <tt>Handler</tt> classes typically use <tt>LogManager</tt> properties to set | |
| 40 | + * default values for the <tt>Handler</tt>'s <tt>Filter</tt>, <tt>Formatter</tt>, | |
| 41 | + * and <tt>Level</tt>. See the specific documentation for each concrete | |
| 42 | + * <tt>Handler</tt> class. | |
| 43 | + * | |
| 44 | + * | |
| 45 | + * @since 1.4 | |
| 46 | + */ | |
| 47 | + | |
| 48 | +public abstract class Handler { | |
| 49 | + private static final int offValue = Level.OFF.intValue(); | |
| 50 | + private LogManager manager = LogManager.getLogManager(); | |
| 51 | + private Filter filter; | |
| 52 | + private Formatter formatter; | |
| 53 | + private Level logLevel = Level.ALL; | |
| 54 | + private ErrorManager errorManager = new ErrorManager(); | |
| 55 | + private String encoding; | |
| 56 | + | |
| 57 | + // Package private support for security checking. When sealed | |
| 58 | + // is true, we access check updates to the class. | |
| 59 | + boolean sealed = true; | |
| 60 | + | |
| 61 | + /** | |
| 62 | + * Default constructor. The resulting <tt>Handler</tt> has a log | |
| 63 | + * level of <tt>Level.ALL</tt>, no <tt>Formatter</tt>, and no | |
| 64 | + * <tt>Filter</tt>. A default <tt>ErrorManager</tt> instance is installed | |
| 65 | + * as the <tt>ErrorManager</tt>. | |
| 66 | + */ | |
| 67 | + protected Handler() { | |
| 68 | + } | |
| 69 | + | |
| 70 | + /** | |
| 71 | + * Publish a <tt>LogRecord</tt>. | |
| 72 | + * <p> | |
| 73 | + * The logging request was made initially to a <tt>Logger</tt> object, | |
| 74 | + * which initialized the <tt>LogRecord</tt> and forwarded it here. | |
| 75 | + * <p> | |
| 76 | + * The <tt>Handler</tt> is responsible for formatting the message, when and | |
| 77 | + * if necessary. The formatting should include localization. | |
| 78 | + * | |
| 79 | + * @param record description of the log event. A null record is | |
| 80 | + * silently ignored and is not published | |
| 81 | + */ | |
| 82 | + public abstract void publish(LogRecord record); | |
| 83 | + | |
| 84 | + /** | |
| 85 | + * Flush any buffered output. | |
| 86 | + */ | |
| 87 | + public abstract void flush(); | |
| 88 | + | |
| 89 | + /** | |
| 90 | + * Close the <tt>Handler</tt> and free all associated resources. | |
| 91 | + * <p> | |
| 92 | + * The close method will perform a <tt>flush</tt> and then close the | |
| 93 | + * <tt>Handler</tt>. After close has been called this <tt>Handler</tt> | |
| 94 | + * should no longer be used. Method calls may either be silently | |
| 95 | + * ignored or may throw runtime exceptions. | |
| 96 | + * | |
| 97 | + * @exception SecurityException if a security manager exists and if | |
| 98 | + * the caller does not have <tt>LoggingPermission("control")</tt>. | |
| 99 | + */ | |
| 100 | + public abstract void close() throws SecurityException; | |
| 101 | + | |
| 102 | + /** | |
| 103 | + * Set a <tt>Formatter</tt>. This <tt>Formatter</tt> will be used | |
| 104 | + * to format <tt>LogRecords</tt> for this <tt>Handler</tt>. | |
| 105 | + * <p> | |
| 106 | + * Some <tt>Handlers</tt> may not use <tt>Formatters</tt>, in | |
| 107 | + * which case the <tt>Formatter</tt> will be remembered, but not used. | |
| 108 | + * <p> | |
| 109 | + * @param newFormatter the <tt>Formatter</tt> to use (may not be null) | |
| 110 | + * @exception SecurityException if a security manager exists and if | |
| 111 | + * the caller does not have <tt>LoggingPermission("control")</tt>. | |
| 112 | + */ | |
| 113 | + public void setFormatter(Formatter newFormatter) throws SecurityException { | |
| 114 | + checkAccess(); | |
| 115 | + // Check for a null pointer: | |
| 116 | + newFormatter.getClass(); | |
| 117 | + formatter = newFormatter; | |
| 118 | + } | |
| 119 | + | |
| 120 | + /** | |
| 121 | + * Return the <tt>Formatter</tt> for this <tt>Handler</tt>. | |
| 122 | + * @return the <tt>Formatter</tt> (may be null). | |
| 123 | + */ | |
| 124 | + public Formatter getFormatter() { | |
| 125 | + return formatter; | |
| 126 | + } | |
| 127 | + | |
| 128 | + /** | |
| 129 | + * Set the character encoding used by this <tt>Handler</tt>. | |
| 130 | + * <p> | |
| 131 | + * The encoding should be set before any <tt>LogRecords</tt> are written | |
| 132 | + * to the <tt>Handler</tt>. | |
| 133 | + * | |
| 134 | + * @param encoding The name of a supported character encoding. | |
| 135 | + * May be null, to indicate the default platform encoding. | |
| 136 | + * @exception SecurityException if a security manager exists and if | |
| 137 | + * the caller does not have <tt>LoggingPermission("control")</tt>. | |
| 138 | + * @exception UnsupportedEncodingException if the named encoding is | |
| 139 | + * not supported. | |
| 140 | + */ | |
| 141 | + public void setEncoding(String encoding) | |
| 142 | + throws SecurityException, java.io.UnsupportedEncodingException { | |
| 143 | + checkAccess(); | |
| 144 | + if (encoding != null) { | |
| 145 | + try { | |
| 146 | + if(!java.nio.charset.Charset.isSupported(encoding)) { | |
| 147 | + throw new UnsupportedEncodingException(encoding); | |
| 148 | + } | |
| 149 | + } catch (java.nio.charset.IllegalCharsetNameException e) { | |
| 150 | + throw new UnsupportedEncodingException(encoding); | |
| 151 | + } | |
| 152 | + } | |
| 153 | + this.encoding = encoding; | |
| 154 | + } | |
| 155 | + | |
| 156 | + /** | |
| 157 | + * Return the character encoding for this <tt>Handler</tt>. | |
| 158 | + * | |
| 159 | + * @return The encoding name. May be null, which indicates the | |
| 160 | + * default encoding should be used. | |
| 161 | + */ | |
| 162 | + public String getEncoding() { | |
| 163 | + return encoding; | |
| 164 | + } | |
| 165 | + | |
| 166 | + /** | |
| 167 | + * Set a <tt>Filter</tt> to control output on this <tt>Handler</tt>. | |
| 168 | + * <P> | |
| 169 | + * For each call of <tt>publish</tt> the <tt>Handler</tt> will call | |
| 170 | + * this <tt>Filter</tt> (if it is non-null) to check if the | |
| 171 | + * <tt>LogRecord</tt> should be published or discarded. | |
| 172 | + * | |
| 173 | + * @param newFilter a <tt>Filter</tt> object (may be null) | |
| 174 | + * @exception SecurityException if a security manager exists and if | |
| 175 | + * the caller does not have <tt>LoggingPermission("control")</tt>. | |
| 176 | + */ | |
| 177 | + public void setFilter(Filter newFilter) throws SecurityException { | |
| 178 | + checkAccess(); | |
| 179 | + filter = newFilter; | |
| 180 | + } | |
| 181 | + | |
| 182 | + /** | |
| 183 | + * Get the current <tt>Filter</tt> for this <tt>Handler</tt>. | |
| 184 | + * | |
| 185 | + * @return a <tt>Filter</tt> object (may be null) | |
| 186 | + */ | |
| 187 | + public Filter getFilter() { | |
| 188 | + return filter; | |
| 189 | + } | |
| 190 | + | |
| 191 | + /** | |
| 192 | + * Define an ErrorManager for this Handler. | |
| 193 | + * <p> | |
| 194 | + * The ErrorManager's "error" method will be invoked if any | |
| 195 | + * errors occur while using this Handler. | |
| 196 | + * | |
| 197 | + * @param em the new ErrorManager | |
| 198 | + * @exception SecurityException if a security manager exists and if | |
| 199 | + * the caller does not have <tt>LoggingPermission("control")</tt>. | |
| 200 | + */ | |
| 201 | + public void setErrorManager(ErrorManager em) { | |
| 202 | + checkAccess(); | |
| 203 | + if (em == null) { | |
| 204 | + throw new NullPointerException(); | |
| 205 | + } | |
| 206 | + errorManager = em; | |
| 207 | + } | |
| 208 | + | |
| 209 | + /** | |
| 210 | + * Retrieves the ErrorManager for this Handler. | |
| 211 | + * | |
| 212 | + * @exception SecurityException if a security manager exists and if | |
| 213 | + * the caller does not have <tt>LoggingPermission("control")</tt>. | |
| 214 | + */ | |
| 215 | + public ErrorManager getErrorManager() { | |
| 216 | + checkAccess(); | |
| 217 | + return errorManager; | |
| 218 | + } | |
| 219 | + | |
| 220 | + /** | |
| 221 | + * Protected convenience method to report an error to this Handler's | |
| 222 | + * ErrorManager. Note that this method retrieves and uses the ErrorManager | |
| 223 | + * without doing a security check. It can therefore be used in | |
| 224 | + * environments where the caller may be non-privileged. | |
| 225 | + * | |
| 226 | + * @param msg a descriptive string (may be null) | |
| 227 | + * @param ex an exception (may be null) | |
| 228 | + * @param code an error code defined in ErrorManager | |
| 229 | + */ | |
| 230 | + protected void reportError(String msg, Exception ex, int code) { | |
| 231 | + try { | |
| 232 | + errorManager.error(msg, ex, code); | |
| 233 | + } catch (Exception ex2) { | |
| 234 | + System.err.println("Handler.reportError caught:"); | |
| 235 | + ex2.printStackTrace(); | |
| 236 | + } | |
| 237 | + } | |
| 238 | + | |
| 239 | + /** | |
| 240 | + * Set the log level specifying which message levels will be | |
| 241 | + * logged by this <tt>Handler</tt>. Message levels lower than this | |
| 242 | + * value will be discarded. | |
| 243 | + * <p> | |
| 244 | + * The intention is to allow developers to turn on voluminous | |
| 245 | + * logging, but to limit the messages that are sent to certain | |
| 246 | + * <tt>Handlers</tt>. | |
| 247 | + * | |
| 248 | + * @param newLevel the new value for the log level | |
| 249 | + * @exception SecurityException if a security manager exists and if | |
| 250 | + * the caller does not have <tt>LoggingPermission("control")</tt>. | |
| 251 | + */ | |
| 252 | + public synchronized void setLevel(Level newLevel) throws SecurityException { | |
| 253 | + if (newLevel == null) { | |
| 254 | + throw new NullPointerException(); | |
| 255 | + } | |
| 256 | + checkAccess(); | |
| 257 | + logLevel = newLevel; | |
| 258 | + } | |
| 259 | + | |
| 260 | + /** | |
| 261 | + * Get the log level specifying which messages will be | |
| 262 | + * logged by this <tt>Handler</tt>. Message levels lower | |
| 263 | + * than this level will be discarded. | |
| 264 | + * @return the level of messages being logged. | |
| 265 | + */ | |
| 266 | + public synchronized Level getLevel() { | |
| 267 | + return logLevel; | |
| 268 | + } | |
| 269 | + | |
| 270 | + /** | |
| 271 | + * Check if this <tt>Handler</tt> would actually log a given <tt>LogRecord</tt>. | |
| 272 | + * <p> | |
| 273 | + * This method checks if the <tt>LogRecord</tt> has an appropriate | |
| 274 | + * <tt>Level</tt> and whether it satisfies any <tt>Filter</tt>. It also | |
| 275 | + * may make other <tt>Handler</tt> specific checks that might prevent a | |
| 276 | + * handler from logging the <tt>LogRecord</tt>. It will return false if | |
| 277 | + * the <tt>LogRecord</tt> is null. | |
| 278 | + * <p> | |
| 279 | + * @param record a <tt>LogRecord</tt> | |
| 280 | + * @return true if the <tt>LogRecord</tt> would be logged. | |
| 281 | + * | |
| 282 | + */ | |
| 283 | + public boolean isLoggable(LogRecord record) { | |
| 284 | + int levelValue = getLevel().intValue(); | |
| 285 | + if (record.getLevel().intValue() < levelValue || levelValue == offValue) { | |
| 286 | + return false; | |
| 287 | + } | |
| 288 | + Filter filter = getFilter(); | |
| 289 | + if (filter == null) { | |
| 290 | + return true; | |
| 291 | + } | |
| 292 | + return filter.isLoggable(record); | |
| 293 | + } | |
| 294 | + | |
| 295 | + // Package-private support method for security checks. | |
| 296 | + // If "sealed" is true, we check that the caller has | |
| 297 | + // appropriate security privileges to update Handler | |
| 298 | + // state and if not throw a SecurityException. | |
| 299 | + void checkAccess() throws SecurityException { | |
| 300 | + if (sealed) { | |
| 301 | + manager.checkAccess(); | |
| 302 | + } | |
| 303 | + } | |
| 304 | +} | |