log4j从类中隔离某个级别

Posted 2021-04-11

我想问一下log4j。我在activemq上有log4j的配置文件。我的问题是我想记录我所拥有的每个类的所有INFO级别消息，但我想将所有DEBUG级别消息从“TransportConnection”类记录到另一个文件，同时记录所有更大的消息或等于WARN级别，到rootLogger。

此配置的问题是我从rootLogger中的“TransportConnection”类记录INFO级别消息。我想只将WARN及以上级别传递给rootLogger。

我不想将阈值设置为“out”appender，因为我想要来自其他类的INFO级别消息。

log4j.rootLogger=INFO,out

# Log these warnings
log4j.logger.org.apache.activemq.broker.BrokerRegistry=INFO
log4j.logger.org.apache.activemq.broker.TransportConnection=DEBUG,tc

# Standard logging
log4j.appender.out=org.apache.log4j.RollingFileAppender
log4j.appender.out.file=/var/lib/activemq/log/activemq.log
log4j.appender.out.maxFileSize=10240KB
log4j.appender.out.maxBackupIndex=100
log4j.appender.out.append=true
log4j.appender.out.layout=org.apache.log4j.PatternLayout
log4j.appender.out.layout.ConversionPattern=%d [%-15.15t] %-5p %-30.30c{1} - %m%n

# Transport Connections logging
log4j.appender.tc=org.apache.log4j.RollingFileAppender
log4j.appender.tc.file=/var/lib/activemq/log/tc.log
log4j.appender.tc.maxFileSize=10240KB
log4j.appender.tc.maxBackupIndex=100
log4j.appender.tc.append=true
log4j.appender.tc.layout=org.apache.log4j.PatternLayout
log4j.appender.tc.layout.ConversionPattern=%d [%t] %-5p %-30.30c{1} - %m%n

答案

您可以编写自己的自定义过滤器。我建议实现可能是这样的：

public class MinLevelForParticularClassFilter extends Filter {

    private boolean acceptOnMatch = false;
    private Level level;
    private String className;

    @Override
    public int decide(LoggingEvent event) {
        if (this.className != null && this.level != null) {
            if (event.getLocationInformation().getClassName().startsWith(className)) {
                // this is event for specified class
                if (!event.getLevel().isGreaterOrEqual(this.level)) {
                    // level of event is less than specified level
                    return Filter.DENY;
                }
            }
        }

        if (acceptOnMatch) {
            return Filter.ACCEPT;
        } else {
            return Filter.NEUTRAL;
        }
    }

    public boolean isAcceptOnMatch() { return acceptOnMatch; }
    public void setAcceptOnMatch(boolean acceptOnMatch) { this.acceptOnMatch = acceptOnMatch; }

    public Level getLevel() { return level; }
    public void setLevel(Level level) { this.level = level; }

    public String getClassName() { return className; }
    public void setClassName(String className) { this.className = className; }
}

请注意，如果将“className”变量更改为“packageName”变量，则对于按特定包过滤，实现方式将相同。

XML中的log4j配置（因为属性文件中的配置不支持过滤器）：

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
    <appender name="out" class="org.apache.log4j.RollingFileAppender">
        <param name="File" value="activemq.log" /> 
        <param name="MaxFileSize" value="10240KB" />
        <param name="MaxBackupIndex" value="100" />
        <param name="Append" value="true" />
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%d [%-15.15t] %-5p %-30.30c{1} - %m%n"/> 
        </layout>

        <!-- Apply filter to appender that's destined for root logger -->
        <filter class="com.foo.log4j.filters.MinLevelForParticularClassFilter">
            <param name="Level" value="WARN" />
            <param name="ClassName" value="org.apache.activemq.broker.TransportConnection" />
            <param name="AcceptOnMatch" value="true" />
        </filter>

    </appender>

    <appender name="tc" class="org.apache.log4j.RollingFileAppender">
        <param name="File" value="tc.log" /> 
        <param name="MaxFileSize" value="10240KB" />
        <param name="MaxBackupIndex" value="100" />
        <param name="Append" value="true" />
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%d [%t] %-5p %-30.30c{1} - %m%n"/> 
        </layout>
    </appender>

    <logger name="org.apache.activemq.broker.BrokerRegistry">
        <level value="INFO" />
    </logger>
    <logger name="org.apache.activemq.broker.TransportConnection">
        <level value="DEBUG" />
        <appender-ref ref="tc" />
    </logger>
    <root> 
        <priority value ="INFO" /> 
        <appender-ref ref="out" /> 
    </root> 
</log4j:configuration>