1 /*
   2  * Copyright (c) 2014, 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  * <b>[JDK INTERNAL]</b>
  28  * The {@code sun.util.logger} package defines an internal provider
  29  * whose default naive implementation is replaced by the {@code java.logging}
  30  * module when the {@code java.logging} module is present.
  31  * <p>
  32  * <b>Default Implementation</b>
  33  * <p>
  34  * The JDK default implementation of the System.LoggerFinder will attempt to
  35  * load an installed instance of the {@link sun.util.logger.JdkLoggerProvider}
  36  * defined in this package.
  37  * When the {@code java.util.logging} package is present, this will usually
  38  * resolve to an instance of {@link sun.util.logging.internal.JdkLoggingProvider} -
  39  * which provides an implementation of the Logger whose backend is a
  40  * {@link java.util.logging.Logger java.util.logging.Logger}.
  41  * Configuration can thus be performed by direct access to the regular
  42  * {@code java.util.logging} APIs,
  43  * using {@link java.util.logging.Logger java.util.logging.Logger} and
  44  * {@link java.util.logging.LogManager} to access and configure the backend
  45  * Loggers.
  46  * <br>
  47  * If however {@code java.util.logging} is not linked with the application, then
  48  * the default implementation will return a simple logger that will print out
  49  * all log messages of INFO level and above to the console ({@code System.err}),
  50  * as implemented by the base {@link sun.util.logger.JdkLoggerProvider} class.
  51  * <p>
  52  * <b>Message Levels and Mapping to java.util.logging</b>
  53  * <p>
  54  * The {@link java.lang.System.LoggerFinder} class documentation describe how
  55  * {@linkplain java.lang.System.Logger.Level System.Logger levels} are mapped
  56  * to {@linkplain java.util.logging.Level JUL levels} when {@code
  57  * java.util.logging} is the backend.
  58  * <p>
  59  * <b>Migrating From {@code java.util.logging}</b>
  60  * <p>
  61  * When migrating a class from logging through {@code java.util.logging} to
  62  * logging through the {@link java.lang.System.Logger System Loggers}, there are two
  63  * choices:
  64  * <ol>
  65  * <li>You can use the {@link sun.util.logging.PlatformLogger} which will
  66  * forward log events through a logger obtained from the LoggerFinder - but
  67  * this will bind you to an internal API, and the PlatformLogger only support
  68  * a small subset of the methods defined on {@code java.util.logging.Logger}.
  69  * </li>
  70  * <li>The other possibility is to obtain a {@link java.lang.System.Logger
  71  * System.Logger} instance from the factory methods defined in
  72  * {@link java.lang.System java.lang.System}, and modify
  73  * all the log statements in the class. This requires more work, but will make
  74  * the class use a public and supported interface, as well as making it
  75  * independent from {@code java.util.logging}, even when
  76  * {@code java.util.logging} is the backend.
  77  * </li>
  78  * </ol>
  79  *
  80  * @see sun.util.logger.JdkLoggerProvider
  81  * @see sun.util.logging.internal.JdkLoggingProvider
  82  * @see java.lang.System.LoggerFinder
  83  * @see java.lang.System.Logger
  84  * @see sun.util.logging.PlatformLoggerBridge
  85  * @see sun.util.logging.internal
  86  *
  87  * @since 1.9
  88  */
  89 package sun.util.logger;