| /* |
| * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| |
| package java.util.logging; |
| |
| import java.io.UnsupportedEncodingException; |
| /** |
| * A <tt>Handler</tt> object takes log messages from a <tt>Logger</tt> and |
| * exports them. It might for example, write them to a console |
| * or write them to a file, or send them to a network logging service, |
| * or forward them to an OS log, or whatever. |
| * <p> |
| * A <tt>Handler</tt> can be disabled by doing a <tt>setLevel(Level.OFF)</tt> |
| * and can be re-enabled by doing a <tt>setLevel</tt> with an appropriate level. |
| * <p> |
| * <tt>Handler</tt> classes typically use <tt>LogManager</tt> properties to set |
| * default values for the <tt>Handler</tt>'s <tt>Filter</tt>, <tt>Formatter</tt>, |
| * and <tt>Level</tt>. See the specific documentation for each concrete |
| * <tt>Handler</tt> class. |
| * |
| * |
| * @since 1.4 |
| */ |
| |
| public abstract class Handler { |
| private static final int offValue = Level.OFF.intValue(); |
| private final LogManager manager = LogManager.getLogManager(); |
| |
| // We're using volatile here to avoid synchronizing getters, which |
| // would prevent other threads from calling isLoggable() |
| // while publish() is executing. |
| // On the other hand, setters will be synchronized to exclude concurrent |
| // execution with more complex methods, such as StreamHandler.publish(). |
| // We wouldn't want 'level' to be changed by another thread in the middle |
| // of the execution of a 'publish' call. |
| private volatile Filter filter; |
| private volatile Formatter formatter; |
| private volatile Level logLevel = Level.ALL; |
| private volatile ErrorManager errorManager = new ErrorManager(); |
| private volatile String encoding; |
| |
| // Package private support for security checking. When sealed |
| // is true, we access check updates to the class. |
| boolean sealed = true; |
| |
| /** |
| * Default constructor. The resulting <tt>Handler</tt> has a log |
| * level of <tt>Level.ALL</tt>, no <tt>Formatter</tt>, and no |
| * <tt>Filter</tt>. A default <tt>ErrorManager</tt> instance is installed |
| * as the <tt>ErrorManager</tt>. |
| */ |
| protected Handler() { |
| } |
| |
| /** |
| * Publish a <tt>LogRecord</tt>. |
| * <p> |
| * The logging request was made initially to a <tt>Logger</tt> object, |
| * which initialized the <tt>LogRecord</tt> and forwarded it here. |
| * <p> |
| * The <tt>Handler</tt> is responsible for formatting the message, when and |
| * if necessary. The formatting should include localization. |
| * |
| * @param record description of the log event. A null record is |
| * silently ignored and is not published |
| */ |
| public abstract void publish(LogRecord record); |
| |
| /** |
| * Flush any buffered output. |
| */ |
| public abstract void flush(); |
| |
| /** |
| * Close the <tt>Handler</tt> and free all associated resources. |
| * <p> |
| * The close method will perform a <tt>flush</tt> and then close the |
| * <tt>Handler</tt>. After close has been called this <tt>Handler</tt> |
| * should no longer be used. Method calls may either be silently |
| * ignored or may throw runtime exceptions. |
| * |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have <tt>LoggingPermission("control")</tt>. |
| */ |
| public abstract void close() throws SecurityException; |
| |
| /** |
| * Set a <tt>Formatter</tt>. This <tt>Formatter</tt> will be used |
| * to format <tt>LogRecords</tt> for this <tt>Handler</tt>. |
| * <p> |
| * Some <tt>Handlers</tt> may not use <tt>Formatters</tt>, in |
| * which case the <tt>Formatter</tt> will be remembered, but not used. |
| * <p> |
| * @param newFormatter the <tt>Formatter</tt> to use (may not be null) |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have <tt>LoggingPermission("control")</tt>. |
| */ |
| public synchronized void setFormatter(Formatter newFormatter) throws SecurityException { |
| checkPermission(); |
| // Check for a null pointer: |
| newFormatter.getClass(); |
| formatter = newFormatter; |
| } |
| |
| /** |
| * Return the <tt>Formatter</tt> for this <tt>Handler</tt>. |
| * @return the <tt>Formatter</tt> (may be null). |
| */ |
| public Formatter getFormatter() { |
| return formatter; |
| } |
| |
| /** |
| * Set the character encoding used by this <tt>Handler</tt>. |
| * <p> |
| * The encoding should be set before any <tt>LogRecords</tt> are written |
| * to the <tt>Handler</tt>. |
| * |
| * @param encoding The name of a supported character encoding. |
| * May be null, to indicate the default platform encoding. |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have <tt>LoggingPermission("control")</tt>. |
| * @exception UnsupportedEncodingException if the named encoding is |
| * not supported. |
| */ |
| public synchronized void setEncoding(String encoding) |
| throws SecurityException, java.io.UnsupportedEncodingException { |
| checkPermission(); |
| if (encoding != null) { |
| try { |
| if(!java.nio.charset.Charset.isSupported(encoding)) { |
| throw new UnsupportedEncodingException(encoding); |
| } |
| } catch (java.nio.charset.IllegalCharsetNameException e) { |
| throw new UnsupportedEncodingException(encoding); |
| } |
| } |
| this.encoding = encoding; |
| } |
| |
| /** |
| * Return the character encoding for this <tt>Handler</tt>. |
| * |
| * @return The encoding name. May be null, which indicates the |
| * default encoding should be used. |
| */ |
| public String getEncoding() { |
| return encoding; |
| } |
| |
| /** |
| * Set a <tt>Filter</tt> to control output on this <tt>Handler</tt>. |
| * <P> |
| * For each call of <tt>publish</tt> the <tt>Handler</tt> will call |
| * this <tt>Filter</tt> (if it is non-null) to check if the |
| * <tt>LogRecord</tt> should be published or discarded. |
| * |
| * @param newFilter a <tt>Filter</tt> object (may be null) |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have <tt>LoggingPermission("control")</tt>. |
| */ |
| public synchronized void setFilter(Filter newFilter) throws SecurityException { |
| checkPermission(); |
| filter = newFilter; |
| } |
| |
| /** |
| * Get the current <tt>Filter</tt> for this <tt>Handler</tt>. |
| * |
| * @return a <tt>Filter</tt> object (may be null) |
| */ |
| public Filter getFilter() { |
| return filter; |
| } |
| |
| /** |
| * Define an ErrorManager for this Handler. |
| * <p> |
| * The ErrorManager's "error" method will be invoked if any |
| * errors occur while using this Handler. |
| * |
| * @param em the new ErrorManager |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have <tt>LoggingPermission("control")</tt>. |
| */ |
| public synchronized void setErrorManager(ErrorManager em) { |
| checkPermission(); |
| if (em == null) { |
| throw new NullPointerException(); |
| } |
| errorManager = em; |
| } |
| |
| /** |
| * Retrieves the ErrorManager for this Handler. |
| * |
| * @return the ErrorManager for this Handler |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have <tt>LoggingPermission("control")</tt>. |
| */ |
| public ErrorManager getErrorManager() { |
| checkPermission(); |
| return errorManager; |
| } |
| |
| /** |
| * Protected convenience method to report an error to this Handler's |
| * ErrorManager. Note that this method retrieves and uses the ErrorManager |
| * without doing a security check. It can therefore be used in |
| * environments where the caller may be non-privileged. |
| * |
| * @param msg a descriptive string (may be null) |
| * @param ex an exception (may be null) |
| * @param code an error code defined in ErrorManager |
| */ |
| protected void reportError(String msg, Exception ex, int code) { |
| try { |
| errorManager.error(msg, ex, code); |
| } catch (Exception ex2) { |
| System.err.println("Handler.reportError caught:"); |
| ex2.printStackTrace(); |
| } |
| } |
| |
| /** |
| * Set the log level specifying which message levels will be |
| * logged by this <tt>Handler</tt>. Message levels lower than this |
| * value will be discarded. |
| * <p> |
| * The intention is to allow developers to turn on voluminous |
| * logging, but to limit the messages that are sent to certain |
| * <tt>Handlers</tt>. |
| * |
| * @param newLevel the new value for the log level |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have <tt>LoggingPermission("control")</tt>. |
| */ |
| public synchronized void setLevel(Level newLevel) throws SecurityException { |
| if (newLevel == null) { |
| throw new NullPointerException(); |
| } |
| checkPermission(); |
| logLevel = newLevel; |
| } |
| |
| /** |
| * Get the log level specifying which messages will be |
| * logged by this <tt>Handler</tt>. Message levels lower |
| * than this level will be discarded. |
| * @return the level of messages being logged. |
| */ |
| public Level getLevel() { |
| return logLevel; |
| } |
| |
| /** |
| * Check if this <tt>Handler</tt> would actually log a given <tt>LogRecord</tt>. |
| * <p> |
| * This method checks if the <tt>LogRecord</tt> has an appropriate |
| * <tt>Level</tt> and whether it satisfies any <tt>Filter</tt>. It also |
| * may make other <tt>Handler</tt> specific checks that might prevent a |
| * handler from logging the <tt>LogRecord</tt>. It will return false if |
| * the <tt>LogRecord</tt> is null. |
| * <p> |
| * @param record a <tt>LogRecord</tt> |
| * @return true if the <tt>LogRecord</tt> would be logged. |
| * |
| */ |
| public boolean isLoggable(LogRecord record) { |
| final int levelValue = getLevel().intValue(); |
| if (record.getLevel().intValue() < levelValue || levelValue == offValue) { |
| return false; |
| } |
| final Filter filter = getFilter(); |
| if (filter == null) { |
| return true; |
| } |
| return filter.isLoggable(record); |
| } |
| |
| // Package-private support method for security checks. |
| // If "sealed" is true, we check that the caller has |
| // appropriate security privileges to update Handler |
| // state and if not throw a SecurityException. |
| void checkPermission() throws SecurityException { |
| if (sealed) { |
| manager.checkPermission(); |
| } |
| } |
| } |