Plugin Architecture

Overview

The Fess plugin system allows you to extend core functionality. Plugins are distributed as JAR files and are loaded dynamically.

Plugin Types

Fess supports the following types of plugins:

Type Description
DataStore Content retrieval from new data sources (Box, Slack, etc.)
Script Engine Support for new scripting languages
Web App Web interface extensions
Ingest Data processing during indexing

Plugin Structure

Basic Structure

fess-ds-example/
├── pom.xml
└── src/main/java/org/codelibs/fess/ds/example/
    ├── ExampleDataStore.java      # DataStore implementation
    └── ExampleDataStoreHandler.java # Handler (optional)

pom.xml Example

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
                             http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.codelibs.fess</groupId>
    <artifactId>fess-ds-example</artifactId>
    <version>15.6.0</version>
    <packaging>jar</packaging>

    <name>fess-ds-example</name>
    <description>Example DataStore for Fess</description>

    <properties>
        <fess.version>15.6.0</fess.version>
        <java.version>21</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.codelibs.fess</groupId>
            <artifactId>fess</artifactId>
            <version>${fess.version}</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
</project>

Plugin Registration

DI Container Registration

Plugins are registered via configuration files such as fess_ds.xml:

<component name="exampleDataStore" class="org.codelibs.fess.ds.example.ExampleDataStore">
    <postConstruct name="register"/>
</component>

Auto Registration

Many plugins auto-register using the @PostConstruct annotation:

@PostConstruct
public void register() {
    ComponentUtil.getDataStoreManager().add(this);
}

Plugin Lifecycle

Initialization

  1. JAR file is loaded

  2. DI container initializes components

  3. @PostConstruct methods are called

  4. Plugin is registered with the manager

Shutdown

  1. @PreDestroy methods are called (if defined)

  2. Resources are cleaned up

Dependencies

Fess Core Dependency

<dependency>
    <groupId>org.codelibs.fess</groupId>
    <artifactId>fess</artifactId>
    <version>${fess.version}</version>
    <scope>provided</scope>
</dependency>

External Libraries

Plugins can include their own dependency libraries:

<dependency>
    <groupId>com.example</groupId>
    <artifactId>example-sdk</artifactId>
    <version>1.0.0</version>
</dependency>

Dependency libraries can be distributed with the plugin JAR or bundled into a fat JAR using Maven Shade Plugin.

Configuration Retrieval

Getting from FessConfig

public class ExampleDataStore extends AbstractDataStore {

    @Override
    public String getName() {
        return "Example";
    }

    @Override
    protected void storeData(DataConfig dataConfig, IndexUpdateCallback callback,
            Map<String, String> paramMap, Map<String, String> scriptMap,
            Map<String, Object> defaultDataMap) {

        // Get parameters
        String apiKey = paramMap.get("api.key");
        String baseUrl = paramMap.get("base.url");

        // Get FessConfig
        FessConfig fessConfig = ComponentUtil.getFessConfig();
    }
}

Build and Installation

Build

mvn clean package

Installation

  1. From Admin Console:

    • Go to “System” -> “Plugins” -> “Install”

    • Enter the plugin name and install

  2. Command Line:

    ./bin/fess-plugin install fess-ds-example

  3. Manual:

    • Copy JAR file to plugins/ directory

    • Restart Fess

Debugging

Log Output

private static final Logger logger = LogManager.getLogger(ExampleDataStore.class);

public void someMethod() {
    logger.debug("Debug message");
    logger.info("Info message");
}

Development Mode

During development, you can debug Fess from your IDE:

  1. Debug run the FessBoot class

  2. Include the plugin source in your project

  3. Set breakpoints

Published Plugins

Main plugins published by the Fess project:

Plugin Description
fess-ds-box Box.com connector
fess-ds-dropbox Dropbox connector
fess-ds-slack Slack connector
fess-ds-atlassian Confluence/Jira connector
fess-ds-git Git repository connector
fess-theme-* Custom themes

These plugins are available on GitHub as development references.

Reference