Commons - Logging

Links

http://commons.apache.org/logging/

Maven

Note: (30/11/2007 17:33) Try using version 1.1.1 (ref commons-logging 1.1.1 released…).

The commons-logging-api dependency does not include built in support for other logging frameworks. Logging will go to system error…

<dependency>
  <groupId>commons-logging</groupId>
  <artifactId>commons-logging-api</artifactId>
  <version>1.1</version>
</dependency>

To add support for other logging frameworks (including log4j) add the following:

<dependency>
  <groupId>commons-logging</groupId>
  <artifactId>commons-logging-adapters</artifactId>
  <version>1.1</version>
</dependency>

Commons logging should automatically use log4j if:

you include the commons-logging-adapters artifact (above) into your project.
you include the log4j dependency in your project
create the log4j.properties file.

See sample projects (below)…

Sample Code

package com.sample;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class Wombat {

    private final Log logger = LogFactory.getLog(Wombat.class);

    Integer t;

    Integer oldT;

    public void setTemperature(Integer temperature) {
        oldT = t;
        t = temperature;

        logger.debug("Temperature set to " + t + ". Old temperature was "
                + oldT + ".");

        if (temperature.intValue() > 50) {
            logger.info("Temperature has risen above 50 degrees.");
        }
    }
}

Sample Projects

log4j

~/repo/sample/java/sample-commons-logging/

Simple
```
~/repo/sample/java/sample-commons-logging-simple/
```
No reliance on third party logging frameworks. All logging will go to system.error.

log4j - Version 1.1.3

Use version 1.0.2 of commons logging:

~/repo/sample/java/sample-commons-logging-log4j-v1.1.3/

This appears to work because the commons logging API has not changed.

<dependency>
  <groupId>commons-logging</groupId>
  <artifactId>commons-logging</artifactId>
  <version>1.0.2</version>
</dependency>
<dependency>
  <groupId>log4j</groupId>
  <artifactId>log4j</artifactId>
  <version>1.1.3</version>
</dependency>