Log4j - 如何将特定异常记录到单独的文件中？

Question

我正在使用带有apache tomcat的java应用程序，如果发生特定的camel异常，则需要将其记录到单独的日志文件中。

例如运行日志(app.log)，如果发生特定异常(JMS-131)则需要将其记录到单独的日志文件中(excp.log)

log4j2配置

<Configuration status="DEBUG">
    <Appenders>
        <Console name="LogToConsole" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
        </Console>        
        <RollingFile name="LogToRollingFile" fileName="logs/app.log"
                     filePattern="logs/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log.gz">
            <PatternLayout>
                <Pattern>%d %p %c{1.} [%t] %m%n</Pattern>
            </PatternLayout>
            <Policies>
                <TimeBasedTriggeringPolicy/>
                <SizeBasedTriggeringPolicy size="10 MB"/>
            </Policies>
            <DefaultRolloverStrategy max="100"/>
        </RollingFile>
        <RollingFile name="OtherFile" fileName="logs/excp.log"
                     filePattern="logs/$${date:yyyy-MM}/excp-%d{MM-dd-yyyy}-%i.log.gz">
            <PatternLayout>
                <Pattern>%d %p %c{1.} [%t] %m%n</Pattern>
            </PatternLayout>
            <Policies>
                <TimeBasedTriggeringPolicy/>
                <SizeBasedTriggeringPolicy size="10 MB"/>
            </Policies>
            <DefaultRolloverStrategy max="100"/>
        </RollingFile>
    </Appenders>
    <Loggers>
        <Logger name="com.test" additivity="false">
            <AppenderRef ref="LogToRollingFile"/>
            <AppenderRef ref="LogToConsole"/>
        </Logger>
        <logger name="oracle.jms.AQjmsError" additivity="false">
            <AppenderRef ref="OtherFile"/>
    </logger>
        <Root level="info">
            <AppenderRef ref="LogToConsole"/>
        </Root>
    </Loggers>
</Configuration>

应用程序日志

org.apache.camel.component.jms.DefaultJmsMessageListenerContainer [] - Initiating transaction rollback on listener exception
javax.jms.IllegalStateException: JMS-131: Session is closed
    at oracle.jms.AQjmsError.throwIllegalStateEx(AQjmsError.java:514) ~[aqapi-12.2.0.1.0.jar:?]
    at oracle.jms.AQjmsSession.checkSessionStarted(AQjmsSession.java:5521) ~[aqapi-12.2.0.1.0.jar:?]
    at oracle.jms.AQjmsSession.getTransacted(AQjmsSession.java:1015) ~[aqapi-12.2.0.1.0.jar:?]

我尝试过使用过滤器、RegexFilter 和路由附加程序，但似乎没有任何效果按预期工作。我所能实现的就是从日志中排除特定的异常。

我对此很陌生，非常感谢任何帮助。预先感谢！

Answer 1

Log4j

Message

由以下部分组成：

• 格式和一些参数，它们被插入以给你一个格式化的消息。在你的情况下是：

  Initiating transaction rollback on application exception
  

• 可选的

  Throwable

  ，其格式与

  Throwable#printStackTrace()

  类似：

  javax.jms.IllegalStateException: JMS-131: Session is closed
      at oracle.jms.AQjmsError.throwIllegalStateEx(AQjmsError.java:514) ~[aqapi-12.2.0.1.0.jar:?]
      at oracle.jms.AQjmsSession.checkSessionStarted(AQjmsSession.java:5521) ~[aqapi-12.2.0.1.0.jar:?]
      at oracle.jms.AQjmsSession.getTransacted(AQjmsSession.java:1015) ~[aqapi-12.2.0.1.0.jar:?]
  

RegexFilter

（参见文档）仅匹配格式化（或未格式化）的消息。此过滤器或任何其他标准过滤器均不使用可抛出对象。

幸运的是，Log4j Core 具有很强的可扩展性，编写一个新的过滤器只需几十行：

@Plugin(name = "ThrowableMessageFilter", category = Node.CATEGORY, elementType = Filter.ELEMENT_TYPE)
public class ThrowableMessageFilter extends AbstractFilter {

    @PluginFactory
    public static ThrowableMessageFilter createFilter(@PluginAttribute("regex") final String regex,
            @PluginAttribute("onMatch") final Result onMatch, @PluginAttribute("onMismatch") final Result onMismatch) {
        if (regex == null) {
            LOGGER.error("A regular expression must be provided for ThrowableMessageFilter");
            return null;
        }
        return new ThrowableMessageFilter(Pattern.compile(regex), onMatch, onMismatch);
    }

    private final Pattern pattern;

    private ThrowableMessageFilter(final Pattern pattern, final Result onMatch, final Result onMismatch) {
        super(onMatch, onMismatch);
        this.pattern = pattern;
    }

    private Result filter(final String message) {
        if (message == null) {
            return onMismatch;
        }
        final Matcher m = pattern.matcher(message);
        return m.matches() ? onMatch : onMismatch;
    }

    @Override
    public Result filter(LogEvent event) {
        final Throwable t = event.getThrown();
        return t != null ? filter(t.getMessage()) : onMismatch;
    }
}

然后您可以将其用作：

<Logger name="oracle.jms.AQjmsError" additivity="false">
  <AppenderRef ref="OtherFile">
    <ThrowableMessageFilter regex=".*JMS-131.*"
                            onMatch="ACCEPT"
                            onMismatch="DENY"/>
  </AppenderRef>
</Logger>