Adding Apache Camel to an Eclipse RCP application

Question

I tried to add Apache Camel support in an Eclipse RCP application. With the new Eclipse, I can also add maven repositories in the target platform file, so that is what I did. My target platform contains:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-core</artifactId>
    <version>4.6.0</version>
    <type>jar</type>
</dependency>

I also checked the includeDependency field to include the required dependencies. All is well so far, I get all 20 or so plugins for the camel projects auto-generated. I add them in my manifest files, compile is working, everything is fine. Except when I try to start camel, I get a runtime exception saying No language for 'simple' found(something similar, I don't have the exact stackstrace now).

The problem is this one:

• The simple language is in the core-languages module
• The core-engine module tries to load the simple language(from the core-languages) into the camel context
• core-engine and core-languages are 2 distinct plugins, thus the Equinox classloader will not allow core-engine to see any files in the META-INF folder inside the core-languages module

I can only think of 2 possible solutions for this:

1. Include Apache Camel as a jar dependency. The problem is I don't see any downloadable jar for the core Apache Camel in Maven. I will have to clone the repositories and build my own jar.
2. Build a Maven project that takes all Camel core dependencies and outputs a single rcp plugin containing the dependencies. For this one I don't need to clone the Camel repositories, but I'm not 100% sure I can achieve this.

For both approaches I think is quite cumbersome to add another Camel component afterwards, because it will probably involve modifying the custom project I created to include the new component(assuming core-engine needs to access it to load it into the context). Also I don't see how I can separate the Camel core from the optional components.

Any ideas to make Camel work with Eclipse RCP?

You can find my target platform here: https://github.com/grozadanut/ro.linic.ui/blob/main/target-platform/target-platform.target

And the RCP product is here: https://github.com/grozadanut/ro.linic.ui/blob/main/ro.linic.ui.product/linic.product

Answer 1

I ended up adding all Camel core jars to my ro.linic.ui.camel.core plugin. And to be able to use camel in other plugins I add this ro.linic.ui.camel.core plugin as a dependency and I exported the required packages to be able to use camel code in my other plugins.

I did use Maven to automate downloading the jars, so I don't have to download each one individually. The pom I used:

<project>
<modelVersion>4.0.0</modelVersion>

<parent>
    <relativePath>../pom.xml</relativePath>
    <groupId>ro.linic.tycho</groupId>
    <artifactId>releng</artifactId>
    <version>1.0.0-SNAPSHOT</version>
</parent>

<groupId>ro.linic.ui</groupId>
<artifactId>ro.linic.ui.camel.core</artifactId>
<version>0.0.1</version>
<packaging>eclipse-plugin</packaging>

<dependencyManagement>
    <dependencies>
        <!-- Camel BOM -->
        <dependency>
            <groupId>org.apache.camel</groupId>
            <artifactId>camel-bom</artifactId>
            <version>4.6.0</version>
            <scope>import</scope>
            <type>pom</type>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>

    <dependency>
        <groupId>org.apache.camel</groupId>
        <artifactId>camel-core</artifactId>
    </dependency>

</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <executions>
                <execution>
                    <id>copy-dependencies</id>
                    <phase>prepare-package</phase>
                    <goals>
                        <goal>copy-dependencies</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>${project.build.directory}/${project.build.finalName}.lib
                        </outputDirectory>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Then I took all camel jars from the generated output folder and added them to the manifest, in the Runtime -> Classpath section.