Upgrading from JCS 2.x to 3.0
This document lists a number of things that changed in Commons JCS
3.0.
Minimum Java Requirements
JCS 3.x requires Java 8 to run. It was tested successfully with JDK 14.
Package Names and Maven Coordinates
The Apache Commons project requires a change of the package names
and Maven coordinates on a major release.
So in all your code replace
import org.apache.commons.jcs.*;
with
import org.apache.commons.jcs3.*;
The Maven coordinates change from
<dependency>
<groupId>org.apache.commons.jcs</groupId>
<artifactId>commons-jcs-core</artifactId>
<version>2.2.1</version>
</dependency>
to
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-jcs3-core</artifactId>
<version>3.0</version>
</dependency>
Adjusting the Configuration
Here again, change all package names in configuration entries
from e.g.
jcs.default.cacheattributes=org.apache.commons.jcs.engine.CompositeCacheAttributes
to
jcs.default.cacheattributes=org.apache.commons.jcs3.engine.CompositeCacheAttributes
Logging Abstraction
JCS 3.0 uses its own log abstraction layer. As newer and better
log systems become available, JCS is no longer limited to
commons-logging. As a result, JCS now uses java.util.logging as
default and does not depend on commons-logging anymore.
Optionally, JCS can use Log4j2 as a log system. You can activate
it by providing log4j-core as a dependency, a log configuration
such as log4j2.xml and a system property
As log initialization occurs very early in the startup process,
be sure to add this property before accessing any of JCS' classes.
JCS uses the Java SPI mechanism to find its log systems. If you want
to roll your own, you will need to implement a
org.apache.commons.jcs.log.Log object and a
org.apache.commons.jcs.log.LogFactory
and provide the implementation class in a text file
META-INF/services/org.apache.commons.jcs.log.LogFactory
in your code. Choose a name for your log system and activate it via
the system property as described above.
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