File Path Issue on Windows with OAS 3.1 - Illegal character in opaque part at index

[gexclaude]

We encountered the issue here, when using OpenAPITools Generator (Maven Plugin) after we switched from OAS 3.0.3 to 3.1.0:
OpenAPITools/openapi-generator#18161

As the Issue on OpenAPITools indicates, the error might be in the swagger-parser. At least we see in the stacktrace, that the error happens there. Is this a known issue?

Our full stack trace.

java.net.URISyntaxException: Illegal character in opaque part at index 2: C:\repos\my-project\api/src/main/resources/oas31-api.yaml
at java.net.URI$Parser.fail (URI.java:2995)
at java.net.URI$Parser.checkChars (URI.java:3166)
at java.net.URI$Parser.parse (URI.java:3202)
at java.net.URI.<init> (URI.java:645)
at io.swagger.v3.parser.reference.ReferenceUtils.resolve (ReferenceUtils.java:29)
at io.swagger.v3.parser.reference.ReferenceVisitor.resolveSchemaRef (ReferenceVisitor.java:227)
at io.swagger.v3.parser.reference.ReferenceVisitor.visitSchema (ReferenceVisitor.java:141)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseSchema (OpenAPI31Traverser.java:790)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseMediaType (OpenAPI31Traverser.java:603)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseMap (OpenAPI31Traverser.java:933)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseRequestBody (OpenAPI31Traverser.java:346)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseOperation (OpenAPI31Traverser.java:229)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traversePathItem (OpenAPI31Traverser.java:424)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseMap (OpenAPI31Traverser.java:933)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traversePaths (OpenAPI31Traverser.java:197)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverseOpenApi (OpenAPI31Traverser.java:124)
at io.swagger.v3.parser.reference.OpenAPI31Traverser.traverse (OpenAPI31Traverser.java:65)
at io.swagger.v3.parser.reference.OpenAPIDereferencer31.dereference (OpenAPIDereferencer31.java:74)
at io.swagger.v3.parser.OpenAPIV3Parser.resolve (OpenAPIV3Parser.java:227)
at io.swagger.v3.parser.OpenAPIV3Parser.readContents (OpenAPIV3Parser.java:183)
at io.swagger.v3.parser.OpenAPIV3Parser.readLocation (OpenAPIV3Parser.java:97)
at io.swagger.parser.OpenAPIParser.readLocation (OpenAPIParser.java:16)
at org.openapitools.codegen.config.CodegenConfigurator.toContext (CodegenConfigurator.java:686)
at org.openapitools.codegen.config.CodegenConfigurator.toClientOptInput (CodegenConfigurator.java:744)
at org.openapitools.codegen.plugin.CodeGenMojo.execute (CodeGenMojo.java:940)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:126)
at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:328)
at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute (MojoExecutor.java:316)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:212)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:174)
at org.apache.maven.lifecycle.internal.MojoExecutor.access$000 (MojoExecutor.java:75)
at org.apache.maven.lifecycle.internal.MojoExecutor$1.run (MojoExecutor.java:162)
at org.apache.maven.plugin.DefaultMojosExecutionStrategy.execute (DefaultMojosExecutionStrategy.java:39)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:159)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:105)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:73)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:53)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:118)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:261)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:173)
at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:101)
at org.apache.maven.cli.MavenCli.execute (MavenCli.java:903)
at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:280)
at org.apache.maven.cli.MavenCli.main (MavenCli.java:203)
at jdk.internal.reflect.DirectMethodHandleAccessor.invoke (DirectMethodHandleAccessor.java:103)
at java.lang.reflect.Method.invoke (Method.java:580)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:255)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:201)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:361)
at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:314)
at org.codehaus.classworlds.Launcher.main (Launcher.java:41)

[DaleGardner]

I'm experiencing this same issue with the file path having the wrong slashes

[FBibonne]

I had the same issue in the same context as @gexclaude (same stack trace).

So you probably parse an openapi file with internal references like this :

schema:
  $ref: '#/components/schemas/Departement'

When the parser has to resolve relative location in $ref, it uses the baseUri of the openapi document to locate it. The problem is the parser is not supplied with an URI for the base document. When you use swagger parser with the openapi-generator, the base URI of the document is provided in the <inputSpec> element of the configuration of the openapi-generator-maven-plugin

So, in my context, I changed the <inputSpec> configuration element of the openapi-generator-maven-plugin to an URI and it solves the probelm :

<!-- path after ${project.baseUri} depends of the location of your openapi.yaml file and wether it is packaged or not at build -->
<inputSpec>${project.baseUri}/target/openapi.yaml</inputSpec>

Hope this helps