Chapter 203. Log Component

log:loggingCategory[?options]

Where loggingCategory is the name of the logging category to use. You can append query options to the URI in the following format, ?option=value&option=value&…​

INFO:*Using Logger instance from the the Registry* As of Camel 2.12.4/2.13.1, if there’s single instance of org.slf4j.Logger found in the Registry, the loggingCategory is no longer used to create logger instance. The registered instance is used instead. Also it is possible to reference particular Logger instance using ?logger=#myLogger URI parameter. Eventually, if there’s no registered and URI logger parameter, the logger instance is created using loggingCategory.

For example, a log endpoint typically specifies the logging level using the level option, as follows:

log:org.apache.camel.example?level=DEBUG

The default logger logs every exchange (regular logging). But Camel also ships with the Throughput logger, which is used whenever the groupSize option is specified.

TIP:*Also a log in the DSL* There is also a log directly in the DSL, but it has a different purpose. Its meant for lightweight and human logs. See more details at LogEIP.

The Log component supports 2 options which are listed below.

The Log endpoint is configured using URI syntax:

log:loggerName

with the following path and query parameters:

In the route below we log the incoming orders at DEBUG level before the order is processed:

from("activemq:orders").to("log:com.mycompany.order?level=DEBUG").to("bean:processOrder");

Or using Spring XML to define the route:

<route>
  <from uri="activemq:orders"/>
  <to uri="log:com.mycompany.order?level=DEBUG"/>
  <to uri="bean:processOrder"/>
</route>

In the route below we log the incoming orders at INFO level before the order is processed.

from("activemq:orders").
    to("log:com.mycompany.order?showAll=true&multiline=true").to("bean:processOrder");

In the route below we log the throughput of the incoming orders at DEBUG level grouped by 10 messages.

from("activemq:orders").
    to("log:com.mycompany.order?level=DEBUG&groupSize=10").to("bean:processOrder");

This route will result in message stats logged every 10s, with an initial 60s delay and stats should be displayed even if there isn’t any message traffic.

from("activemq:orders").
    to("log:com.mycompany.order?level=DEBUG&groupInterval=10000&groupDelay=60000&groupActiveOnly=false").to("bean:processOrder");

The following will be logged:

"Received: 1000 new messages, with total 2000 so far. Last group took: 10000 millis which is: 100 messages per second. average: 100"

Available as of Camel 2.19

You can enable security masking for logging by setting logMask flag to true. Note that this option also affects Log EIP.

To enable mask in Java DSL at CamelContext level:

camelContext.setLogMask(true);

And in XML:

<camelContext logMask="true">

You can also turn it on|off at endpoint level. To enable mask in Java DSL at endpoint level, add logMask=true option in the URI for the log endpoint:

from("direct:start").to("log:foo?logMask=true");

And in XML:

<route>
  <from uri="direct:foo"/>
  <to uri="log:foo?logMask=true"/>
</route>

org.apache.camel.processor.DefaultMaskingFormatter is used for the masking by default. If you want to use a custom masking formatter, put it into registry with the name CamelCustomLogMask. Note that the masking formatter must implement org.apache.camel.spi.MaskingFormatter.

Available as of Camel 2.11

With the options outlined in the #Formatting section, you can control much of the output of the logger. However, log lines will always follow this structure:

Exchange[Id:ID-machine-local-50656-1234567901234-1-2, ExchangePattern:InOut,
Properties:{CamelToEndpoint=log://org.apache.camel.component.log.TEST?showAll=true,
CamelCreatedTimestamp=Thu Mar 28 00:00:00 WET 2013},
Headers:{breadcrumbId=ID-machine-local-50656-1234567901234-1-1}, BodyType:String, Body:Hello World, Out: null]

This format is unsuitable in some cases, perhaps because you need to…​

Whenever you require absolute customization, you can create a class that implements the ExchangeFormatter interface. Within the format(Exchange) method you have access to the full Exchange, so you can select and extract the precise information you need, format it in a custom manner and return it. The return value will become the final log message.

You can have the Log component pick up your custom ExchangeFormatter in either of two ways:

Explicitly instantiating the LogComponent in your Registry:

<bean name="log" class="org.apache.camel.component.log.LogComponent">
   <property name="exchangeFormatter" ref="myCustomFormatter" />
</bean>

<bean name="logFormatter" class="com.xyz.MyCustomExchangeFormatter" />

<bean name="logFormatter" class="com.xyz.MyCustomExchangeFormatter" scope="prototype"/>

<to uri="log:foo?param1=foo&amp;param2=100"/>

<to uri="log:bar?param1=bar&amp;param2=200"/>

Improvement as of Camel 2.12.4/2.13.1

When using Log component inside OSGi (e.g., in Karaf), the underlying logging mechanisms are provided by PAX logging. It searches for a bundle which invokes org.slf4j.LoggerFactory.getLogger() method and associates the bundle with the logger instance. Without specifying custom org.sfl4j.Logger instance, the logger created by Log component is associated with camel-core bundle.

In some scenarios it is required that the bundle associated with logger should be the bundle which contains route definition. To do this, either register single instance of org.slf4j.Logger in the Registry or reference it using logger URI parameter.