Grizzly and Jersey standalone jar

Question

I am trying to package Grizzly with Jersey as a single jar using Maven shade plugin. But I always get the message No container provider supports the type class org.gla

Answer 1

I just made the stupid mistake. Configure maven-assembly-plugin in pom as well.

Assembly seems to replace META-INF/services and override "com.sun.jersey.server.impl.container.grizzly2.GrizzlyContainerProvider " in File com.sun.jersey.spi.container.ContainerProvider

As guide http://maven.apache.org/plugins/maven-assembly-plugin/ mentioned, If your project wants to package your artifact in an uber-jar, the assembly plugin provides only basic support. For more control, use the Maven Shade Plugin.

  <!-- mvn assembly:assembly -->
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-assembly-plugin</artifactId>
            <configuration>
                <archive>
                    <manifest>
                        <addClasspath>true</addClasspath>
                        <mainClass>XXX.DaemonMain</mainClass>
                    </manifest>
                </archive>
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
            </configuration>
        </plugin>  

Answer 2

The error looks like the plugin is not merging the META-INF/services records from different jars correctly - if there are multiple files with the same name in META-INF/services directory of several jars, they need to be merged, not replaced one by the other. Check if that is the case.

Answer 3

The following links helped me figuring out the solution below:

• http://maven.apache.org/guides/mini/guide-assemblies.html
• http://maven.apache.org/plugins/maven-assembly-plugin/descriptor-refs.html
• How can I merge resource files in a Maven assembly?

especially the answer

• https://stackoverflow.com/a/11331222/1497139

Instead of using the jar-with-dependencies as the descriptorRef of your assembly-plugin configuration you create our own e.g. in src/assembly/depmerge.xml (see below). This assembly configuration will add a containerDescriptorHandler that cares for the META-INF/services.

run

mvn clean compile assembly:single

to get a jar file in target which you can call with

java -jar target/x.y.-version-jar-with-dependencies.jar

pom.xml:

      <plugin>
            <artifactId>maven-assembly-plugin</artifactId>
            <version>2.5.3</version>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>${mainClass}</mainClass>
                    </manifest>
                </archive>
          <descriptor>src/assembly/depmerge.xml</descriptor>
          </configuration>
        </plugin>

src/assembly/depmerge.xml:

<!-- 
 see http://maven.apache.org/guides/mini/guide-assemblies.html 
 see http://maven.apache.org/plugins/maven-assembly-plugin/descriptor-refs.html 
-->
<assembly
    xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd">
    <!-- TODO: a jarjar format would be better -->
    <id>jar-with-dependencies-and-services</id>
    <formats>
        <format>jar</format>
    </formats>
    <includeBaseDirectory>false</includeBaseDirectory>
    <dependencySets>
        <dependencySet>
            <outputDirectory>/</outputDirectory>
            <useProjectArtifact>true</useProjectArtifact>
            <unpack>true</unpack>
            <scope>runtime</scope>
        </dependencySet>
    </dependencySets>
    <!-- 
      https://stackoverflow.com/questions/1607220/how-can-i-merge-resource-files-in-a-maven-assembly
     -->
    <containerDescriptorHandlers>
        <containerDescriptorHandler>
            <handlerName>metaInf-services</handlerName>
        </containerDescriptorHandler>
    </containerDescriptorHandlers>
</assembly>