Log4j 2.6 发布 Java 日志组件

Log4j 2.6 发布了，本次发布的一些新特性：

o LOG4J2-1270: (GC) Added support for garbage-free logging in steady state.
This includes Async Loggers and logging synchronously to the console and to a file,
but does not include the AsyncAppender. This release makes the GelfLayout and
the main patterns in the PatternLayout garbage-free.
o LOG4J2-1297: (GC) Added manual page on garbage-free logging.
o LOG4J2-1373: (GC) Update Logger wrapper Generator tool to generate methods for the new
Logger methods.
o LOG4J2-1326: (GC) Added methods to the Logger interface for logging CharSequence messages.

o LOG4J2-1344: (GC) FileAppender, RollingFileAppender and MemoryMappedFileAppender are now
also garbage-free by default.
o LOG4J2-1278: (GC) Added unrolled varargs methods to Logger API, added Unbox utility to
avoid auto-boxing when logging primitive values.
o LOG4J2-1271: (GC) Add MessageFactory that avoid allocation by reusing a cached ParameterizedMessage
instance.
o LOG4J2-1293: (GC) Add interface StringBuilderFormattable to enable converting Messages
and parameters to text without allocating temporary objects.
ParameterizedMessage, ObjectMessage, SimpleMessage and ThreadDumpMessage now implement
StringBuilderFormattable.
o LOG4J2-1274: (GC) Add encode(LogEvent, ByteBufferDestination) method to Layout API to enable
converting LogEvents to bytes without creating temporary objects.
o LOG4J2-1362: Added a YAML layout. Thanks to Gary Gregory.
o LOG4J2-1179: Documented benchmark results comparing Log4j 2 performance to other logging
libraries.
o LOG4J2-1011: Document dependencies for layouts.
o LOG4J2-621: Pattern to drop first N package parts. Thanks to Lee Theobald, Kamal Mettananda,
Gary Gregory.
o LOG4J2-494: Support merging configurations to for a composite configuration. Thanks to
Philipp Knobel.
o LOG4J2-1357: Option to not log stack traces for logged Throwables in GelfLayout.
o LOG4J2-1348: Add an AutoCloseable ThreadContext class: CloseableThreadContext. Thanks to
Greg Thomas, Gary Gregory.
o LOG4J2-1299: Add pattern converter for thread id and priority in PatternLayout.
o LOG4J2-124: Add shutdown methods to LogManager.
o LOG4J2-1221: Added async logger Timeout wait strategy and made this the default wait strategy
for async loggers.
This prevents a rare deadlock that may occur on Solaris. Thanks to Michael Barker.

o LOG4J2-1080: Added option to discard events below a certain log level if the async logger
ring buffer
or async appender queue is full.
o LOG4J2-1237: Make PatternLayout header and footer accept a pattern. Thanks to Mike Calmus,
Gary Gregory.
o LOG4J2-1244: Make header and footer values customizable in JSONLayout. Thanks to Anshu
Garg, Remko Popma, Gary Gregory.
o LOG4J2-1245: Make CSV Layout header and footers accept patterns.
o LOG4J2-1192: Dynamic Subject for SMTP Appender. Thanks to Jörg Bretschneider, Gary Gregory.

o LOG4J2-1277: FormattedMessage, MessageFormatMessage and StringFormattedMessage should support
passing in a Locale to ensure appropriate formatting. Thanks to Gary Gregory, Ludovic Hochet.

o LOG4J2-1303: Add documentation links to runtime dependencies in each component intro page.

o LOG4J2-1252: JeroMqAppender should support layouts.
o LOG4J2-1217: PatternLayout option to limit length of text. Thanks to Thies Wellpott.
o LOG4J2-1133: Add JNDI lookup documentation.
o LOG4J2-1169: PatternLayout: Possible variable substitution in equals substitution parameter.
Thanks to Gerald Kritzinger.

完整改进记录，可以在这里查看。