Schema references lead to "URI is not absolute" Exception

[LumnitzF]

In the old version, one could reference a JSON schema from within another schema using the name, defined in the RAML "schemas" section. When trying the same approach now, the generation leads to an exception:

Failed to execute goal org.raml:raml-to-jaxrs-maven-plugin:2.0.0:generate on project test-api: Error generating Java classes from: null: URI is not absolute -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.raml:raml-to-jaxrs-maven-plugin:2.0.0:generate on project test-api: Error generating Java classes from: null
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:216)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:862)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:286)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:197)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoExecutionException: Error generating Java classes from: null
	at org.raml.jaxrs.codegen.maven.RamlJaxrsCodegenMojo.execute(RamlJaxrsCodegenMojo.java:212)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
	... 20 more
Caused by: java.lang.IllegalArgumentException: URI is not absolute
	at java.net.URI.toURL(URI.java:1088)
	at org.jsonschema2pojo.ContentResolver.resolve(ContentResolver.java:67)
	at org.jsonschema2pojo.SchemaStore.create(SchemaStore.java:48)
	at org.jsonschema2pojo.SchemaStore.create(SchemaStore.java:116)
	at org.jsonschema2pojo.rules.SchemaRule.apply(SchemaRule.java:59)
	at org.jsonschema2pojo.rules.SchemaRule.apply(SchemaRule.java:30)
	at org.jsonschema2pojo.rules.PropertyRule.apply(PropertyRule.java:75)
	at org.jsonschema2pojo.rules.PropertyRule.apply(PropertyRule.java:43)
	at org.jsonschema2pojo.rules.PropertiesRule.apply(PropertiesRule.java:64)
	at org.jsonschema2pojo.rules.PropertiesRule.apply(PropertiesRule.java:32)
	at org.jsonschema2pojo.rules.ObjectRule.apply(ObjectRule.java:115)
	at org.jsonschema2pojo.rules.ObjectRule.apply(ObjectRule.java:66)
	at org.jsonschema2pojo.rules.TypeRule.apply(TypeRule.java:90)
	at org.jsonschema2pojo.rules.TypeRule.apply(TypeRule.java:40)
	at org.jsonschema2pojo.rules.SchemaRule.apply(SchemaRule.java:73)
	at org.jsonschema2pojo.rules.SchemaRule.apply(SchemaRule.java:30)
	at org.jsonschema2pojo.SchemaMapper.generate(SchemaMapper.java:134)
	at org.raml.jaxrs.generator.JsonSchemaTypeGenerator.output(JsonSchemaTypeGenerator.java:60)
	at org.raml.jaxrs.generator.builders.AbstractTypeGenerator.output(AbstractTypeGenerator.java:27)
	at org.raml.jaxrs.generator.CurrentBuild.generate(CurrentBuild.java:126)
	at org.raml.jaxrs.generator.RamlScanner.handle(RamlScanner.java:94)
	at org.raml.jaxrs.generator.RamlScanner.handle(RamlScanner.java:74)
	at org.raml.jaxrs.generator.RamlScanner.handle(RamlScanner.java:55)
	at org.raml.jaxrs.codegen.maven.RamlJaxrsCodegenMojo.execute(RamlJaxrsCodegenMojo.java:210)
	... 22 more

The RAML:

#%RAML 1.0
title: URI is not absolute
baseUri: https://foo/bar

mediaType: application/json

types: 
  A: !include model/A.schema.json
  B: !include model/B.schema.json
     
/foo:
  get:
    responses:
      200:
        body:
          type: A

A.schema.json

{
	"$schema": "http://json-schema.org/draft-04/schema#",
	"type": "object",
	"properties": {
		"refB": {
			"$ref": "B"
		}
	}
}

B.schema.json

{
	"$schema": "http://json-schema.org/draft-04/schema#",
	"type": "object",
	"properties": {}
}

When I reference B using the direct path (e.g. file:src/main/resources/raml/model/B.schema.json) it works. However using relative paths (e.g. B.schema.json, or file:B.schema.json) the exception is thrown again.

Is this feature dropped? Always using the complete path makes the schemas super ugly, and glued to the complete package structure.

[dcrossleyau]

That seems closely related to #202

[giacgbj]

What about this issue? I can't find a way to define the refs which works both using the plugin and api-workbench for Atom.

[jpbelang]

Sorry, slipped through the cracks. I'll look into it and see if we can do something tonight.

[giacgbj]

@jpbelang In your solution, please consider that the workaround suggested by @frl7082 doesn't work if you have a multi-module Maven project and you run the build from the parent instead of the module which uses this plugin.

When do you expect to release a version which solves this issue?

[jpbelang]

I've had a look.
We delegate all or the json schema stuff to jsonschema2pojo. The difficulty is that j2p resolves the $refs by itself.

https://github.com/joelittlejohn/jsonschema2pojo/wiki/Reference#ref

I think the only solution would be to use classpath: or one of the other synonyms. I'm currently having problems adjusting the classpath in the maven plugin.