log4j2

PatternLayout 配置说明： http://logging.apache.org/log4j/2.x/manual/layouts.html#PatternLayout

pattern 转义符处理类： org.apache.logging.log4j.core.pattern.PatternConverter

例如：

@Plugin(name = "DatePatternConverter", category = PatternConverter.CATEGORY)
@ConverterKeys({"d", "date"})
@PerformanceSensitive("allocation")
public final class DatePatternConverter extends LogEventPatternConverter implements ArrayPatternConverter {
...
}

开启 log4j2 框架内部 debug 日志：

<configuration monitorInterval="60" status="debug">