Log4j 2.8 发布，Java 日志组件

Log4j 2.8 发布了。Log4j是Apache的一个开放源代码项目，通过使用Log4j，我们可以控制日志信息输送的目的地是控制台、文件、GUI组件、甚至是套接口服务器、NT的事件记录器、UNIX Syslog守护进程等;我们也可以控制每一条日志的输出格式;通过定义每一条日志信息的级别，我们能够更加细致地控制日志的生成过程。最令人感兴趣的就是，这些可以通过一个配置文件来灵活地进行配置，而不需要修改应用的代码。

此版本包含几个错误修复和新功能。新功能包括能够使 RollingFileAppender 日志直接写入到归档文件。

有关新功能和修复的更多详细信息，参见下面：

新特性：

LOG4J2-1032: Make DefaultRolloverStrategy more efficent when renaming files. Add nomax option to the fileIndex attribute.
LOG4J2-1101: RollingFileAppender now supports omitting the file name and writing directly to the archive files.
LOG4J2-1243: Allow default value in property to be a Lookup.
LOG4J2-1787: Document how to exclude transitive conflicting dependencies in Maven and Gradle.
LOG4J2-1773: Add StatusLoggerRule to allow unit tests to set a status level.
LOG4J2-424: Add non-string data type support to JdbcAppender via new ColumnMapping plugin.
LOG4J2-1771: Add a Builder to ColumnConfig and deprecate ColumnConfig.createColumnConfig().
LOG4J2-1770: Add a Builder to JdbcAppender and deprecate JdbcAppender.createAppender().
LOG4J2-1764: Use MethodHandle in ContextDataFactory cached constructor.
LOG4J2-1730: Add Apache Cassandra appender and ColumnMapping plugin.
LOG4J2-1759: Add TypeConverter for java.util.UUID.
LOG4J2-1758: Add TypeConverter for java.nio.file.Path.
LOG4J2-1755: Add TypeConverter and constraint validators for java.net.InetAddress and port numbers.
LOG4J2-969: Refactor SyslogAppender so that Layout is a Plugin element.
LOG4J2-1660: Added public method ThreadContext::getThreadContextMap; removed class ThreadContextAccess.
LOG4J2-1379: Add documentation regarding YAML configuration format.
LOG4J2-1718: Introduce marker interface AsynchronouslyFormattable.
LOG4J2-1681: Introduce interfaces IndexedStringMap and IndexedReadOnlyStringMap, supporting garbage-free iteration over sorted map.
LOG4J2-1695: Add a Builder to ScriptPatternSelector and deprecate ScriptPatternSelector.createSelector().
LOG4J2-1696: Add a Builder to MarkerPatternSelector and deprecate MarkerPatternSelector.createSelector().
LOG4J2-1697: Add a SerializerBuilder to PatternLayout and deprecate PatternLayout.createSerializer().
LOG4J2-1701: Add a Builder to RandomAccessFileAppender and deprecate RandomAccessFileAppender.createAppender().
LOG4J2-1703: Add a Builder to MemoryMappedFileAppender and deprecate MemoryMappedFileAppender.createAppender().
LOG4J2-1704: Add a Builder to RollingRandomAccessFileAppender and deprecate RollingRandomAccessFileAppender.createAppender().
LOG4J2-1709: Add a Builder to SyslogAppender and deprecate SyslogAppender.createAppender().
LOG4J2-1707: Allow TCP Socket Appender to set socket options.
LOG4J2-1708: Allow Secure Socket Appender to set socket options.
LOG4J2-1737: Add a Builder to SyslogLayout and deprecate SyslogLayout.createLayout(Facility, boolean, String, Charset).
LOG4J2-1738: Add a Builder to JsonLayout and deprecate org.apache.logging.log4j.core.layout.JsonLayout.createLayout(Configuration, boolean, boolean, boolean, boolean, boolean, boolean, String, String, Charset, boolean).
LOG4J2-1739: Add Builder to KafkaAppender and deprecate KafkaAppender.createAppender(Layout, Filter, String, boolean, String, Property[], Configuration).
LOG4J2-1733: Add SyncSend attribute to KafkaAppender (as in KafkaLog4jAppender). Thanks to Vincent Tieleman.