JarCastingDynamic Extensions for Alfresco
Add OSGi based hot-deploy functionality and Spring annotation based configuration to Alfresco.
Introduction
Rapid development of Alfresco repository extensions in Java. Deploy your code in seconds, not minutes. Life is too short for endless server restarts.
Dynamic Extensions adds an OSGi container to the Alfresco repository, enabling live deployment of Java code, with no need to restart the server. Alfresco itself is not "OSGi-fied" in any way; the OSGi container runs on top of the core Alfresco platform.
Standard Alfresco Platform Extensions use Spring XML based configuration. With Dynamic Extensions, developers have the ability to create Alfresco Platform Extensions using Spring's annotations based configuration.
Installing Dynamic Extensions in Alfresco
Dynamic Extensions (DE) is distributed as an Alfresco Module Package (AMP) extension that can be installed in Alfresco.
Installing the Dynamic Extensions AMP
To support multiple Alfresco versions, different AMPs for each minor Alfresco version update are build and distributed.
E.g. if you are working with Alfresco 6.0.7-ga, you should use the alfresco-dynamic-extensions-repo-60 artifact.
Maven Central Coordinates
All required artifacts, including the AMP to be installed in Alfresco, are available in Maven Central.
<dependency>
<groupId>eu.xenit</groupId>
<artifactId>alfresco-dynamic-extensions-repo-${alfresco-version}</artifactId>
<version>${latest-dynamic-extensions-version}</version>
<type>amp</type>
</dependency>
alfrescoAmp "eu.xenit:alfresco-dynamic-extensions-repo-${alfrescoVersion}:${dynamicExtensionsVersion}@amp"
These artifacts can be used to automatically install Dynamic Extensions in Alfresco using e.g. the Alfresco Maven SDK or the Alfresco Docker Gradle Plugins
Manual download and install
- Download the latest Dynamic Extensions AMP.
- Use the Module Management Tool to install the AMP in the Alfresco repository of your choosing.
- After restarting Alfresco, open the Control Panel: http://localhost:8080/alfresco/service/dynamic-extensions/.
- Accessing the Control Panel requires an admin account.
Supported Alfresco versions
Dynamic Extensions is systematically integration-tested against:
- Alfresco Enterprise & Community 6.2 (Requires hotfix, see below)
- Alfresco Enterprise & Community 6.1 (Requires hotfix, see below)
- Alfresco Enterprise & Community 6.0
- Alfresco Enterprise & Community 5.2
- Alfresco Enterprise & Community 5.1
- Alfresco Enterprise & Community 5.0
Integration tests are currently only executed on our private Jenkins build server.
Known Alfresco issues that impact Dynamic Extensions
Alfresco 6.1 / 6.2 - wrong version of 'Commons annotations' used
When using DE on Alfresco 6.1 or 6.2, it is possible that it fails to startup due to following error:Caused by: java.lang.NoSuchMethodError: javax.annotation.Resource.lookup()Ljava/lang/String;
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.<init>(CommonAnnotationBeanPostProcessor.java:621)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.lambda$buildResourceMetadata$0(CommonAnnotationBeanPostProcessor.java:383)
at org.springframework.util.ReflectionUtils.doWithLocalFields(ReflectionUtils.java:719)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.buildResourceMetadata(CommonAnnotationBeanPostProcessor.java:365)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.findResourceMetadata(CommonAnnotationBeanPostProcessor.java:350)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(CommonAnnotationBeanPostProcessor.java:298)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyMergedBeanDefinitionPostProcessors(AbstractAutowireCapableBeanFactory.java:1044)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:550)
The root cause is for this problem is that Alfresco has multiple implementations of the JSR 250 specification, 'Common Annotations' in the WEB-INF/lib/ folder:
- javax.annotation:javax.annotation-api
- javax.annotation:jsr250-api
- org.apache.geronimo.specs:geronimo-annotation_1.0_spec
Only the first one is up to date and contains the correct implementation of the Resource class. The other two versions contain an old implementation of the Resource class, causing the provided error to be thrown by Spring internally.
This is only an issue as of Java 11 (Alfresco 6.1) because earlier versions had an correct implementation of the Resource class embedded in the distribution, and the bootstrap classloader has the highest priority.
This issue has been reported to Alfresco: MNT-20557. Waiting for Alfresco to fix the issue, following workarounds can be used to make DE work on Alfresco 6.1 and 6.2:
- Remove the
jsr250-apiandgeronimo-annotation_1.0_specjars from theWEB-INF/libfolder of the Alfresco webapp. - Install this hotfix AMP in your Alfresco distribution, which will overwrite the
jsr250-apiandgeronimo-annotation_1.0_specjars with empty jars.
Example Dynamic Extensions based Alfresco Platform extension
This example Web Script examines a node and passes information to a Freemarker template:
@Component
@WebScript
public ExampleWebScript {
@Autowired
private NodeService nodeService;
@Uri("/show-node")
// Example: http://localhost/alfresco/service/show-node?nodeRef=workspace://SpacesStore/12345
public Map<String, Object> displayNodeName(@RequestParam NodeRef nodeRef) {
Map<String, Object> model = new HashMap<String, Object>();
model.put("properties", nodeService.getProperties(nodeRef));
return model; // Model is passed to Freemarker template.
}
}
Note that this is an annotation Web Script. These types of Web Script are configured through Java annotations instead of *.desc.xml descriptors. Annotation Web Scripts are similar to Spring MVC's annotation-based controllers.
Here's the accompanying Freemarker template fragment:
<table>
<#list properties?keys as name>
<tr>
<th>${name}</th>
<td>${properties[name]!''}</td>
</tr>
</#list>
</table>
This is all the code that is required; there's no need for Spring XML config or Web Script XML descriptors. Hot-reloading and reducing configuration overhead are not particularly novel concepts in the Java development world at large. Essentially, Dynamic Extensions modernizes the development of Alfresco repository extensions.
The example above may be trivial, but the point is that, behind the scenes, services are still wired together through Spring and handled by the Web Script framework. Conceptually there is no real difference between a Dynamic Extension and a regular Alfresco extension. There's just less overhead and more convenience.
Documentation
Please checkout the documentation for further instructions.
License
This project is licensed under the Apache V2 License - see the LICENSE file for details.
