记录错误到stderr和调试，信息到标准输出log4j

Question

我想添加日志记录到我正在开发的应用程序，使用apache log4j。在这一点上，我想重定向所有级别INFO的日志消息，并且将（TRACE，DEBUG）的所有日志消息重定向到标准输出以及WARN和以上（错误，致命）的所有其他日志消息到stderr。 例如：

... 
logger.info("Processing at some point"); // must be written to stdout 
logger.debug("Point x was processed"); // must be written to stdout 
logger.warn("Incorrect point config"); // must be written only to stderr 
logger.error("Exception occurred at point x"); // must be written only to stderr 

那么应该怎么我的log4j.properties文件？它在这里是怎样看待这个momment：

log4j.rootLogger=DEBUG, stdout, stderr 

# configure stdout 
# set the conversion pattern of stdout 
# Print the date in ISO 8601 format 
log4j.appender.stdout = org.apache.log4j.ConsoleAppender 
log4j.appender.stdout.Threshold = DEBUG 
log4j.appender.stdout.Target = System.out 
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout 
log4j.appender.stdout.layout.ConversionPattern = %-5p %d [%t][%F:%L] : %m%n 

# configure stderr 
# set the conversion pattern of stdout 
# Print the date in ISO 8601 format 
log4j.appender.stderr = org.apache.log4j.ConsoleAppender 
log4j.appender.stderr.Threshold = WARN 
log4j.appender.stderr.Target = System.err 
log4j.appender.stderr.layout = org.apache.log4j.PatternLayout 
log4j.appender.stderr.layout.ConversionPattern = %-5p %d [%t][%F:%L] : %m%n 

具有上述配置的问题是，logger.error（）...在标准输出打印了。

Answer 1

每乔恩斯基特以前的帖子在Post

unfortunately there is no maximum threshold, so wherever you get debug messages, you also get warning messages. That's a bit of a pain, IMO.

Answer 2

解决下面还属性文件格式。诀窍是让过滤器定义正确。 Log4j properties info here

原来的尝试，修改过滤WARN &错误：

log4j.rootLogger=TRACE, stdout, stderr 

# configure stdout 
# set the conversion pattern of stdout 
# Print the date in ISO 8601 format 
log4j.appender.stdout = org.apache.log4j.ConsoleAppender 
log4j.appender.stdout.Threshold = TRACE 
log4j.appender.stdout.Target = System.out 
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout 
log4j.appender.stdout.layout.ConversionPattern = %-5p %d [%t][%F:%L] : %m%n 
log4j.appender.stdout.filter.filter1=org.apache.log4j.varia.LevelRangeFilter 
log4j.appender.stdout.filter.filter1.levelMin=TRACE 
log4j.appender.stdout.filter.filter1.levelMax=INFO 

# configure stderr 
# set the conversion pattern of stdout 
# Print the date in ISO 8601 format 
log4j.appender.stderr = org.apache.log4j.ConsoleAppender 
log4j.appender.stderr.Threshold = WARN 
log4j.appender.stderr.Target = System.err 
log4j.appender.stderr.layout = org.apache.log4j.PatternLayout 
log4j.appender.stderr.layout.ConversionPattern = %-5p %d [%t][%F:%L] : %m%n 

Answer 3

1. 而不是使用的.properties配置，您必须使用.xml配置。
2. 在.xml配置文件中放入一个名为“filter”的类型为“org.apache.log4j.varia.LevelRangeFilter”的元素，并设置其参数LevelMax和LevelMin。

例如，下面的.xml配置定义了两个appender：stdout，stderr。 stdout会将所有级别小于或等于INFO的日志打印到stdout，并且stderr会将所有级别大于INFO的日志打印到stderr。

<?xml version="1.0" encoding="UTF-8"?> 
<!-- 
    Document : log4j.xml 
    Created on : 13 Δεκέμβριος 2011, 3:55 μμ 
    Author  : elitex 
    Description : Purpose of the document follows. 
--> 
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd" > 
<log4j:configuration> 
    <appender name="stderr" class="org.apache.log4j.ConsoleAppender"> 
     <param name="threshold" value="warn" /> 
     <param name="target" value="System.err"/> 
     <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="%-5p %d [%t][%F:%L] : %m%n" /> 
     </layout> 
    </appender> 
    <appender name="stdout" class="org.apache.log4j.ConsoleAppender"> 
     <param name="threshold" value="debug" /> 
     <param name="target" value="System.out"/> 
     <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="%-5p %d [%t][%F:%L] : %m%n" /> 
     </layout> 
     <filter class="org.apache.log4j.varia.LevelRangeFilter"> 
      <param name="LevelMin" value="debug" /> 
      <param name="LevelMax" value="info" /> 
     </filter> 
    </appender> 
    <root> 
     <priority value="debug"></priority> 
     <appender-ref ref="stderr" /> 
     <appender-ref ref="stdout" /> 
    </root> 
</log4j:configuration> 

欲了解更多信息看：http://www.laliluna.de/articles/posts/log4j-tutorial.html

Answer 4

另一个例子利用log4j2的ThresholdFilter标记。

<Console name="ConsoleERR" target="SYSTEM_ERR"> 
    <PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level - %msg%n"/> 
    <ThresholdFilter level="ERROR" onMatch="ACCEPT" onMismatch="DENY"/> 
</Console> 

请参阅doc。

Answer 5

这是的logback配置这不正是你问什么（！）：

<?xml version="1.0" encoding="UTF-8"?> 
<configuration debug="true" scan="true" scanPeriod="30 seconds"> 

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> 
     <target>System.out</target> 
     <filter class="ch.qos.logback.classic.filter.LevelFilter"> 
      <level>INFO</level> 
      <onMatch>ACCEPT</onMatch> 
      <onMismatch>DENY</onMismatch> 
     </filter> 
     <encoder> 
      <pattern> 
       %-4relative [%thread] %-5level %logger - %msg%n 
      </pattern> 
     </encoder> 
    </appender> 

    <appender name="STDERR" class="ch.qos.logback.core.ConsoleAppender"> 
     <target>System.err</target> 
     <filter class="ch.qos.logback.classic.filter.ThresholdFilter"> 
      <level>WARN</level> 
     </filter> 
     <encoder> 
      <pattern> 
       %-4relative [%thread] %-5level %logger - %msg%n 
      </pattern> 
     </encoder> 
    </appender> 

    <root level="${LOGBACK_ROOT_LEVEL:-INFO}"> 
     <appender-ref ref="STDOUT" /> 
     <appender-ref ref="STDERR" /> 
    </root> 

</configuration>