| /* |
| * 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.util.Objects; |
| import java.io.UnsupportedEncodingException; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| |
| /** |
| * A {@code Handler} object takes log messages from a {@code Logger} 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 {@code Handler} can be disabled by doing a {@code setLevel(Level.OFF)} |
| * and can be re-enabled by doing a {@code setLevel} with an appropriate level. |
| * <p> |
| * {@code Handler} classes typically use {@code LogManager} properties to set |
| * default values for the {@code Handler}'s {@code Filter}, {@code Formatter}, |
| * and {@code Level}. See the specific documentation for each concrete |
| * {@code Handler} 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; |
| |
| /** |
| * Default constructor. The resulting {@code Handler} has a log |
| * level of {@code Level.ALL}, no {@code Formatter}, and no |
| * {@code Filter}. A default {@code ErrorManager} instance is installed |
| * as the {@code ErrorManager}. |
| */ |
| protected Handler() { |
| } |
| |
| /** |
| * Package-private constructor for chaining from subclass constructors |
| * that wish to configure the handler with specific default and/or |
| * specified values. |
| * |
| * @param defaultLevel a default {@link Level} to configure if one is |
| * not found in LogManager configuration properties |
| * @param defaultFormatter a default {@link Formatter} to configure if one is |
| * not specified by {@code specifiedFormatter} parameter |
| * nor found in LogManager configuration properties |
| * @param specifiedFormatter if not null, this is the formatter to configure |
| */ |
| Handler(Level defaultLevel, Formatter defaultFormatter, |
| Formatter specifiedFormatter) { |
| |
| LogManager manager = LogManager.getLogManager(); |
| String cname = getClass().getName(); |
| |
| final Level level = manager.getLevelProperty(cname + ".level", defaultLevel); |
| final Filter filter = manager.getFilterProperty(cname + ".filter", null); |
| final Formatter formatter = specifiedFormatter == null |
| ? manager.getFormatterProperty(cname + ".formatter", defaultFormatter) |
| : specifiedFormatter; |
| final String encoding = manager.getStringProperty(cname + ".encoding", null); |
| |
| AccessController.doPrivileged(new PrivilegedAction<Void>() { |
| @Override |
| public Void run() { |
| setLevel(level); |
| setFilter(filter); |
| setFormatter(formatter); |
| try { |
| setEncoding(encoding); |
| } catch (Exception ex) { |
| try { |
| setEncoding(null); |
| } catch (Exception ex2) { |
| // doing a setEncoding with null should always work. |
| // assert false; |
| } |
| } |
| return null; |
| } |
| }, null, LogManager.controlPermission); |
| } |
| |
| /** |
| * Publish a {@code LogRecord}. |
| * <p> |
| * The logging request was made initially to a {@code Logger} object, |
| * which initialized the {@code LogRecord} and forwarded it here. |
| * <p> |
| * The {@code Handler} 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 {@code Handler} and free all associated resources. |
| * <p> |
| * The close method will perform a {@code flush} and then close the |
| * {@code Handler}. After close has been called this {@code Handler} |
| * 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 {@code LoggingPermission("control")}. |
| */ |
| public abstract void close() throws SecurityException; |
| |
| /** |
| * Set a {@code Formatter}. This {@code Formatter} will be used |
| * to format {@code LogRecords} for this {@code Handler}. |
| * <p> |
| * Some {@code Handlers} may not use {@code Formatters}, in |
| * which case the {@code Formatter} will be remembered, but not used. |
| * |
| * @param newFormatter the {@code Formatter} to use (may not be null) |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have {@code LoggingPermission("control")}. |
| */ |
| public synchronized void setFormatter(Formatter newFormatter) throws SecurityException { |
| checkPermission(); |
| formatter = Objects.requireNonNull(newFormatter); |
| } |
| |
| /** |
| * Return the {@code Formatter} for this {@code Handler}. |
| * @return the {@code Formatter} (may be null). |
| */ |
| public Formatter getFormatter() { |
| return formatter; |
| } |
| |
| /** |
| * Set the character encoding used by this {@code Handler}. |
| * <p> |
| * The encoding should be set before any {@code LogRecords} are written |
| * to the {@code Handler}. |
| * |
| * @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 {@code LoggingPermission("control")}. |
| * @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 {@code Handler}. |
| * |
| * @return The encoding name. May be null, which indicates the |
| * default encoding should be used. |
| */ |
| public String getEncoding() { |
| return encoding; |
| } |
| |
| /** |
| * Set a {@code Filter} to control output on this {@code Handler}. |
| * <P> |
| * For each call of {@code publish} the {@code Handler} will call |
| * this {@code Filter} (if it is non-null) to check if the |
| * {@code LogRecord} should be published or discarded. |
| * |
| * @param newFilter a {@code Filter} object (may be null) |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have {@code LoggingPermission("control")}. |
| */ |
| public synchronized void setFilter(Filter newFilter) throws SecurityException { |
| checkPermission(); |
| filter = newFilter; |
| } |
| |
| /** |
| * Get the current {@code Filter} for this {@code Handler}. |
| * |
| * @return a {@code Filter} 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 {@code LoggingPermission("control")}. |
| */ |
| 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 {@code LoggingPermission("control")}. |
| */ |
| 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 {@code Handler}. 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 |
| * {@code Handlers}. |
| * |
| * @param newLevel the new value for the log level |
| * @exception SecurityException if a security manager exists and if |
| * the caller does not have {@code LoggingPermission("control")}. |
| */ |
| 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 {@code Handler}. Message levels lower |
| * than this level will be discarded. |
| * @return the level of messages being logged. |
| */ |
| public Level getLevel() { |
| return logLevel; |
| } |
| |
| /** |
| * Check if this {@code Handler} would actually log a given {@code LogRecord}. |
| * <p> |
| * This method checks if the {@code LogRecord} has an appropriate |
| * {@code Level} and whether it satisfies any {@code Filter}. It also |
| * may make other {@code Handler} specific checks that might prevent a |
| * handler from logging the {@code LogRecord}. It will return false if |
| * the {@code LogRecord} is null. |
| * |
| * @param record a {@code LogRecord} |
| * @return true if the {@code LogRecord} 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. |
| // We check that the caller has appropriate security privileges |
| // to update Handler state and if not throw a SecurityException. |
| void checkPermission() throws SecurityException { |
| manager.checkPermission(); |
| } |
| } |