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{include:Uses Commons Logging}

h3. URI format

{code}
log:loggingCategory[?options]
{code}

Where *loggingCategory* is the name of the logging category to use. You can append query options to the URI in the following format, {{

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:

{code}
log:org.apache.camel.example?level=DEBUG
{code}

groupDelay and groupActiveOnly are only applicable when using groupInterval.

For older versions of Camel that do not support the showFiles or showStreams properties above, you can set the following property instead on the CamelContext to log both stream and file bodies:

camelContext.getProperties().put(Exchange.LOG_DEBUG_BODY_STREAMS, true);

{code}
{tip}


h3. Regular logger sample
In the route below we log the incoming orders at {{DEBUG}} level before the order is processed:
{code:java}
from("activemq:orders")
  .to("log:com.mycompany.order?level=DEBUG")
  .to("bean:processOrder");
{code}

 to define the route:
{code:xml}
  <route>
    <from uri="activemq:orders"/>
    <to uri="log:com.mycompany.order?level=DEBUG"/>
    <to uri="bean:processOrder"/>
  </route> 
{code}

h3. Regular logger with formatter sample
In the route below we log the incoming orders at {{INFO}} level before the order is processed.
{code:java}

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

h3. Throughput logger with groupSize sample
In the route below we log the throughput of the incoming orders at {{DEBUG}} level grouped by 10 messages.
{code:java}

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

h3. Throughput logger with groupInterval sample

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.

{code:java}

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

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]
{code}

 to...

* ... filter the headers and properties that are printed, to strike a balance between insight and verbosity.
* ... adjust the log message to whatever you deem most readable.
* ... tailor log messages for digestion by log mining systems, e.g. Splunk.
* ... print specific body types differently.
* ... etc.

Whenever you require absolute customization, you can create a class that implements the [{{ExchangeFormatter}}|http://camel.apache.org/maven/current/camel-core/apidocs/org/apache/camel/spi/ExchangeFormatter.html] 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:*

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

*Convention over configuration:*

Simply by registering a bean with the name {{logFormatter}}; the Log Component is intelligent enough to pick it up automatically.

{code}

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

NOTE: the {{ExchangeFormatter}} gets applied to *all Log endpoints within that Camel Context*. If you need different ExchangeFormatters for different endpoints, just instantiate the LogComponent as many times as needed, and use the relevant bean name as the endpoint prefix.

From *Camel 

 define the "logForamtter" as prototype scoped so its not shared if you have different parameters, eg:

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

{code}
<to uri="log:foo?param1=foo&amp;param2=100"/>
<!-- ... -->
<to uri="log:bar?param1=bar&amp;param2=200"/>
{code}

{include:Endpoint See Also}
* [Tracer]
* [How do I use log4j]
* [How do I use Java 1.4 logging]
* [LogEIP] for using {{log}} directly in the DSL for human