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/**

 * Provides the classes and interfaces of

 * the Java™ 2 platform's core logging facilities.

 * The central goal of the logging APIs is to support maintaining and servicing

 * software at customer sites.

 *

 * <P>

 * There are four main target uses of the logs:

 * </P>

 *

 * <OL>

 *    <LI> <I>Problem diagnosis by end users and system administrators</I>.

 *           This consists of simple logging of common problems that can be fixed

 *           or tracked locally, such as running out of resources, security failures,

 *           and simple configuration errors.

 *

 *    <LI> <I>Problem diagnosis by field service engineers</I>. The logging information

 *            used by field service engineers may be considerably more complex and

 *            verbose than that required by system administrators.  Typically such information

 *            will require extra logging within particular subsystems.

 *

 *    <LI> <I>Problem diagnosis by the development organization</I>.

 *          When a problem occurs in the field, it may be necessary to return the captured logging

 *          information to the original development team for diagnosis. This logging

 *          information may be extremely detailed and fairly inscrutable. Such information might include

 *          detailed tracing on the internal execution of particular subsystems.

 *

 *    <LI> <I>Problem diagnosis by developers</I>. The Logging APIs may also be

 *            used to help debug an application under development. This may

 *            include logging information generated by the target application

 *            as well as logging information generated by lower-level libraries.

 *            Note however that while this use is perfectly reasonable,

 *            the logging APIs are not intended to replace the normal debugging

 *            and profiling tools that may already exist in the development environment.

 * </OL>

 *

 * <p>

 * The key elements of this package include:

 * <UL>

 *    <LI> <I>Logger</I>: The main entity on which applications make

 *                 logging calls. A Logger object is used to log messages

 *                 for a specific system or application

 *                 component.

 *    <LI> <I>LogRecord</I>: Used to pass logging requests between the logging

 *                    framework and individual log handlers.

 *    <LI> <I>Handler</I>: Exports LogRecord objects to a variety of destinations

 *                  including memory, output streams, consoles, files, and sockets.

 *                  A variety of Handler subclasses exist for this purpose. Additional Handlers

 *                  may be developed by third parties and delivered on top of the core platform.

 *    <LI> <I>Level</I>: Defines a set of standard logging levels that can be used

 *                       to control logging output. Programs can be configured to output logging

 *                       for some levels while ignoring output for others.

 *    <LI> <I>Filter</I>: Provides fine-grained control over what gets logged,

 *                        beyond the control provided by log levels. The logging APIs support a general-purpose

 *                        filter mechanism that allows application code to attach arbitrary filters to

 *                        control logging output.

 *

 *    <LI> <I>Formatter</I>: Provides support for formatting LogRecord objects. This

 *                           package includes two formatters, SimpleFormatter and

 *                           XMLFormatter, for formatting log records in plain text

 *                           or XML respectively. As with Handlers, additional Formatters

 *                           may be developed by third parties.

 * </UL>

 * <P>

 * The Logging APIs offer both static and dynamic configuration control.

 * Static control enables field service staff to set up a particular configuration and then re-launch the

 * application with the new logging settings. Dynamic control allows for updates to the

 * logging configuration within a currently running program. The APIs also allow for logging to be

 * enabled or disabled for different functional areas of the system. For example,

 * a field service engineer might be interested in tracing all AWT events, but might have no interest in

 * socket events or memory management.

 * </P>

 *

 * <h2>Null Pointers</h2>

 * <p>

 * In general, unless otherwise noted in the javadoc, methods and

 * constructors will throw NullPointerException if passed a null argument.

 * The one broad exception to this rule is that the logging convenience

 * methods in the Logger class (the config, entering, exiting, fine, finer, finest,

 * log, logp, logrb, severe, throwing, and warning methods)

 * will accept null values

 * for all arguments except for the initial Level argument (if any).

 *

 * <H2>Related Documentation</H2>

 * <P>

 * For an overview of control flow,

 * please refer to the

 * {@extLink logging_overview Java Logging Overview}

 * </P>

 *

 * @since 1.4

 */

package java.util.logging;