相关的概念

• Loggers 输出的日志级别
  • ERROR, WARN, INFO, DEBUG
• Appenders 输出到哪里
  • org.apache.log4j.ConsoleAppender 控制台
  • org.apache.log4j.FileAppender 文件
  • org.apache.log4j.DailyRollingFileAppender 每天产生一个文件
• Layouts 输出格式
  • org.apache.log4j.HTMLLayout Html格式
  • org.apache.log4j.PatternLayout 自定义格式
  • org.apache.log4j.SimpleLayout 简单的输出格式
  • org.apache.log4j.TTCCLayout 包含时间, 线程, 类别等信息

配置格式

log4j.rootLogger = 级别, appenderName1, appenderName2

log4j.appender.appenderName1 = 对应的类名
log4j.appender.appenderName1.选项 = 值
log4j.appender.appenderName1.layout = 对应的类名
log4j.appender.appenderName1.layout.选项 = 值

log4j.appender.appenderName2 = 对应的类名
log4j.appender.appenderName2.选项 = 值
log4j.appender.appenderName2.layout = 对应的类名
log4j.appender.appenderName3.layout.选项 = 值

配置实例

log4j.rootLogger = DEBUG,console,file

log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.target = System.out
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern = %d{ABSOLUTE} %5p %c{1}:%L - %m%n

log4j.appender.file = org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.File = logs/log.log
log4j.appender.file.Append = true
log4j.appender.file.Threshold = Error
log4j.appender.file.layout = org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} %5p %c{1}:%L - %m%n