OpenAPIV3Parser#getExtensions() not finding extensions on OSGi

[fmoussallam]

I am using the swagger-parser-v3 library from within an OSGi bundle.

The issue I am facing is that the ServiceLoader.load(SwaggerParserExtension.class) mechanism uses the current thread's class loader (see https://docs.oracle.com/javase/8/docs/api/java/util/ServiceLoader.html#load-java.lang.Class-).

With that default behavior, getExtensions() does not return anything, and I can't parse v2 specifications.

I can workaround this by forcing the current thread classloader to SwaggerParserExtension.getClass().getClassLoader() but that is ugly.

Would it be possible to add a ParseOption to allow selecting the class loader?

Thank you

[gracekarina]

Hi, please provide us with a PR and a failing test where we can see what you mean. Thanks

[fmoussallam]

This test would fail for a v2 swagger.json spec:

    public void testIssue1003() {
    	ClassLoader ctcl = Thread.currentThread().getContextClassLoader();
    	try {
    		final ClassLoader cl = new URLClassLoader(new URL[] {});
    		Thread.currentThread().setContextClassLoader(cl);
            assertNotNull(new OpenAPIV3Parser().read("src/test/resources/swagger.json"));
    	} finally {
    		Thread.currentThread().setContextClassLoader(ctcl);
    	}
    }

Problem is where to place that test. OpenAPIV3ParserTest does not have any loadable extension on its classpath anyway.

Are there any tests actually loading extensions?

Thanks

[gracekarina]

Hi, can you place it at swagger-parser module, and test? what do you mean here: Would it be possible to add a ParseOption to allow selecting the class loader?

[cvgaviao]

In order to the new version to work with OSGi you need to install a bundle providing an OSGi ServiceLoader Mediator implementation. The one that I know is Aries SPI Fly.

[fmoussallam]

I propose #1068 for your review.

The unit test is not great but at least it verifies that both classloaders are given a chance to provide extensions. This was separately tested in an OSGi environment.

[gracekarina]

closed by #1068.

[jmini]

@fmoussallam: I have the feeling there is the exact same issue with OpenAPIParser:

swagger-parser/modules/swagger-parser/src/main/java/io/swagger/parser/OpenAPIParser.java

Lines 41 to 51 in 0a4ed0b

	protected List<SwaggerParserExtension> getExtensions() {
	List<SwaggerParserExtension> extensions = new ArrayList<>();
	ServiceLoader<SwaggerParserExtension> loader = ServiceLoader.load(SwaggerParserExtension.class);
	Iterator<SwaggerParserExtension> itr = loader.iterator();
	while (itr.hasNext()) {
	extensions.add(itr.next());
	}
	extensions.add(0, new OpenAPIV3Parser());
	return extensions;
	}

Can you confirm this?

[fmoussallam]

Humm, definitely looks like the same issue. I was not aware OpenAPIParser was upward compatible with V3 (which I find a little bit confusing I have to say)

[jmini]

@fmoussallam: is this also a problem in an OSGi context? Do you want to push a similar patch for that as well?

[fmoussallam]

Sure will do. I would also want to submit another PR for #997 which is trivial. Is that ok?