Yasson Module - JSON-B with Yasson

[MatthiasReining]

My current Java EE 8 app runs on Wildfly 16. I'm just using stock application server without defining a dedicated JAX-RS/JSON library. This mean the server use Yasson as JSON-B implementation. Therefore there is no dependency for Jackson on the project classpath.

Without a Jackson dependency enunciate render the data types of the JAX-RS interface just with (custom). Is there an option that the right objects are rendered also when using Yasson?

Are there plans for a "Module Yasson" beside "Jersey" and "Jackson" ?

[stoicflame]

There's currently no support for JSON-B/Yasson. That's a good enhancement request, though. I'll track it here.

In the meantime, you could force-enable the jackson module and see how well the data types get processed.

[MatthiasReining]

Thanks for having a look to Yasson :-)

I'm not sure, but for me it looks like that the jackson module have no forceEnable attribute. But when I link jackson dependency just to a mvn profile that generates the docu by the enunciate mvn plugin, the data types are detected and rendered. Therefore, this workaround could help.

[stoicflame]

You can force-enable by explicitly setting disabled to false:

<enunciate>
  <modules>
    <jackson disabled="false"/>

[MatthiasReining]

if i only set disabled to false the data type is just rendered as Custom ...

My workaround looks like that I add a mvn profile for generating the docu:

<profile>
	<id>rest-api</id>

	<dependencies>
		<dependency>
			<groupId>org.codehaus.jackson</groupId>
			<artifactId>jackson-mapper-asl</artifactId>
			<version>1.9.13</version>
			<scope>provided</scope>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<!-- create and package rest api docu -->
			<plugin>
				<groupId>com.webcohesion.enunciate</groupId>
				<artifactId>enunciate-maven-plugin</artifactId>
				<version>${enunciate.version}</version>
				<executions>
					<execution>
						<phase>${phase-build-rest-api}</phase>
						<goals>
							<goal>docs</goal>
						</goals>
						<configuration>
							<configFile>${basedir}/src/assembly/enunciate.xml</configFile>
						</configuration>
					</execution>
				</executions>
				<configuration>
					<configFile>${basedir}/src/assembly/enunciate.xml</configFile>
				</configuration>
				<dependencies>
					<dependency>
						<groupId>javax</groupId>
						<artifactId>javaee-api</artifactId>
						<version>${javaee.version}</version>
					</dependency>
					<dependency>
						<groupId>com.webcohesion.enunciate</groupId>
						<artifactId>enunciate-lombok</artifactId>
						<version>${enunciate.version}</version>
					</dependency>
					<dependency>
						<groupId>dk.jyskebank.tooling.enunciate</groupId>
						<artifactId>enunciate-openapi</artifactId>
						<version>${enunciate-openapi.version}</version>
					</dependency>
				</dependencies>
			</plugin>

			<plugin>
				<artifactId>maven-assembly-plugin</artifactId>
				<version>${assembly.plugin.version}</version>
				<configuration>
					<descriptors>
						<descriptor>src/assembly/apidoc-assembly.xml</descriptor>
					</descriptors>
				</configuration>
				<executions>
					<execution>
						<phase>${phase-build-rest-api}</phase>
						<goals>
							<goal>single</goal>
						</goals>
					</execution>
				</executions>
			</plugin>
		</plugins>
	</build>
</profile>

and start the generation within the Jenkins pipeline by

mvn com.webcohesion.enunciate:enunciate-maven-plugin:docs -Prest-api

[stoicflame]

Weird. With the module force-enabled, the run without the profile should be the same as the run with the profile. What's the difference between the profile and the non-profile configuration? Is it just the dependency on jackson?

[MatthiasReining]

Yes. Without dependency the data type results always in Custom. I just use the profile to avoid the Jackson depency to my normal code base.

[stoicflame]

I put some effort into investigating the jackson module enablement behavior. I can confirm that force-enabling the jackson module works, even with jackson not on the classpath. Here's a diff I applied to enunciate-sample to prove it:

diff --git a/enunciate.xml b/enunciate.xml
index b162cc0..cf578e9 100644
--- a/enunciate.xml
+++ b/enunciate.xml
@@ -16,6 +16,7 @@
     <docs>
       <download file="LICENSE" name="Apache II" description="The license governing this API" showLink="true"/>
     </docs>
+    <jackson disabled="false"/>
     <java-xml-client>
       <package-conversions>
         <convert from="com.ifyouwannabecool" to="com.ifyouwannabecool.client"/>
diff --git a/pom.xml b/pom.xml
index 08c659b..1b18337 100644
--- a/pom.xml
+++ b/pom.xml
@@ -75,12 +75,6 @@
       <version>${jaxb.version}</version>
     </dependency>
 
-    <dependency>
-      <groupId>com.fasterxml.jackson.jaxrs</groupId>
-      <artifactId>jackson-jaxrs-json-provider</artifactId>
-      <version>${jackson.version}</version>
-    </dependency>
-
     <dependency>
       <groupId>org.glassfish.jersey.containers</groupId>
       <artifactId>jersey-container-servlet</artifactId>
diff --git a/src/main/java/com/ifyouwannabecool/App.java b/src/main/java/com/ifyouwannabecool/App.java
index 0d6d4db..000b14b 100644
--- a/src/main/java/com/ifyouwannabecool/App.java
+++ b/src/main/java/com/ifyouwannabecool/App.java
@@ -1,6 +1,5 @@
 package com.ifyouwannabecool;
 
-import com.fasterxml.jackson.jaxrs.json.JacksonJsonProvider;
 import org.glassfish.jersey.server.ResourceConfig;
 import org.glassfish.jersey.servlet.ServletProperties;
 
@@ -11,7 +10,6 @@ public class App extends ResourceConfig {
 
     public App() {
         packages(App.class.getPackage().getName(), "com.webcohesion.enunciate.rt");
-        register(JacksonJsonProvider.class);
         property(ServletProperties.FILTER_FORWARD_ON_404, true);
     }
 }

If you can modify that patch to expose the problem, I'd be happy to take another look. Although I'd suggest opening another thread if you find a bug or something. We'll keep this thread open to track Yasson support.

[stoicflame]

This enhancement is currently seeking a sponsor. If anybody is willing to sponsor the work, reach out to me and I'd be happy to pick it up.