Failing to load draft-07 type schemas (probably lower ones too)

[elisherer]

Using SchemaStore::loadSchema(Object document) get stuck in an infinite loop trying to fetch the meta-schema of draft-07.
Getting logs:

net.jimblackler.jsonschemafriend.SchemaStore: Was not valid JSON: http://json-schema.org/draft-07/schema

It began today (2023-10-02) and probably is related to a change made at https://json-schema.org/blog/posts/new-website.

Issue

• It seems that the issue is with the http stream not following 301 redirects.
• Also getting into an infinite loop instead of failing fast makes the service unresponsive.

Reproduce

• I think any piece of code (like the one in the README.md) which loads draft-07 schema will fail.

Workaround

Workaround 1:

Using a url rewriter (a bit dangerous)

public class SchemaForceHttpsUrlRewriter implements UrlRewriter {
    @Override
    public URI rewrite(URI in) {
        if (in.toString().startsWith("http:")) {
            return URI.create(in.toString().replaceFirst("http:", "https:"));
        }
        return in;
    }
}

Initialize store with store = new SchemaStore(new SchemaForceHttpsUrlRewriter());

Workaround 2:

not using a validator when using loadSchema

store.loadSchema(obj, null);

Workaround 3:

Storing the meta schemas as resources in the module and pre-loading them before calling loadSchema
Using SchemaStore::store(URI uri, Object document)
or SchemaStore::register(URI path, Schema schema)

(Maybe as a premanent solution it would be best to bundle all meta-schema draft-03+ with the library and prevent even trying to download them)

[jimblackler]

Thanks for the fix. A word of warning for others, you may need to delete your cache if you have this issue, even after the patch. The location of the cache is based on the System property java.io.tmpdir.