Configuring Logback

Configuring Logback¶

Egeria's clients use SLF4J for developer logging. This technology expects a logging destination to be provided. If you see the following error message when you run your utility, then you need to provide a logging destination.

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

Logback is a technology that provides a logging destination for SLF4J. It is included in your utility if its dependency is added to your pom.xml file.

<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <scope>compile</scope>
    <version>${logback.version}</version>
</dependency>

Controlling the level of developer logging is handled by a logback.xml file located in a resource directory at top level of your module.

Creating the logback.xml file

Select your top-level code directory (module) and using the right-mouse menu select New then Directory.
Select New Directory

Enter the directory name as resources. Enter name

Select the new resources directory. Use the right-mouse menu to select Mark Directory as and then Resources Root. Make resources root

The icon of the directory changes.

Select the resources directory again. Use the right-mouse menu to select New and then File. New file

Enter the filename of logback.xml and click ok Enter name

The content of the logback.xml defines the level of logging. This is a suggested starting set of values for logback that turns developer logging off. You can the enable the logging as required.

<?xml version="1.0" encoding="UTF-8"?>

<!-- SPDX-License-Identifier: Apache-2.0 -->
<!-- Copyright Contributors to the ODPi Egeria project. -->

<configuration>

  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
  </appender>

  <root level="OFF">
    <appender-ref ref="STDOUT" />
  </root>
</configuration>

If your utility includes unit tests, you will need to create a logback-test.xml file in the same resources directory with similar content.