log4j layout ConversionPattern符号说明

如果使用pattern布局就要指定的打印信息的具体格式ConversionPattern，打印参数如下：

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%m 输出代码中指定的消息

%p 输出优先级，即DEBUG，INFO，WARN，ERROR，FATAL

%r 输出自应用启动到输出该log信息耗费的毫秒数

%c 输出所属的类目，通常就是所在类的全名

%t 输出产生该日志事件的线程名

%n 输出一个回车换行符，Windows平台为“rn”，Unix平台为“n”

%d 输出日志时间点的日期或时间，默认格式为ISO8601，也可以在其后指定格式，比如：%d{yyyy MMM dd HH:mm:ss,SSS}，输出类似：2002年10月18日 ：10：28，921

%l 输出日志事件的发生位置，包括类目名、发生的线程，以及在代码中的行数。

%x Used to output the NDC (nested diagnostic context) associated with the thread that generated the logging event

%X Used to output the MDC (mapped diagnostic context) associated with the thread that generated the logging event for specified key

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示例：

log4j.appender.R.layout.ConversionPattern=%d{yyyy-MMM-dd HH:mm:ss,SSS}-[TS] %p %t %c - %m%n

输出：2012-06-06 10:45:30,000-[TS] INFO thread30 TestClass - 记录的日志

PATTERN FORMATS GLOSSARY

%n - newline

%m - your log message

%p - message priority (FATAL, ERROR, WARN, INFO, DEBUG or custom)

%r - millisecs since program started running

%% - percent sign in output

SOME MORE CLUTTER IN YOUR LOG

%c - name of your category (logger), %c{2} will outputs last two components

%t - name of current thread

%x - Nested Diagnostic Context (NDC) (you supply it)

SLOW PERFORMANCE FORMATS

%d - date and time, also %d{ISO8601}, %d{DATE}, %d{ABSOLUTE},

%d{HH:mm:ss,SSS}, %d{dd MMM yyyy HH:mm:ss,SSS} and so on

%l - Shortcut for %F%L%C%M

%F - Java source file name

%L - Java source line number

%C - Java class name, %C{1} will output the last one component

%M - Java method name

FORMAT MODIFIERS

%-any_letter_above - Left-justify in min. width (default is right-justify)

%20any_letter_above - 20 char. min. width (pad with spaces if reqd.)

%.30any_letter_above- 30 char. max. width (truncate beginning if reqd.)

%-10.10r - Example. Left-justify time elapsed within 10-wide field.

Truncate from beginning if wider than 10 characters.