[JENA-1176] JSON-LD @context parsing fails due to outdated HTTPClient

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: Jena 3.1.0
• Labels: httpclient jsonld
• Assignee: Andy Seaborne
• Reporter: Stian Soiland-Reyes
• Created: 09/May/16 12:53
• Updated: 14/May/16 09:51
• Resolved: 10/May/16 07:53

Description

Raised by Francois:

public class TestJsonLDReader {

	@Test public final void test() {
		String jsonld = "{\"@id\":\"_:b0\",\"@type\":\"http://schema.org/Person\",\"name\":\"John
Doe\",\"@context\":\"http://schema.org/\"}";
		StringReader reader = new StringReader(jsonld);
		Model m = ModelFactory.createDefaultModel();
		m.read(reader, null, "JSON-LD");
		m.write(System.out, "TURTLE");
	}
}

Fails with:

java.lang.NoSuchMethodError: org.apache.http.impl.client.cache.CacheConfig.custom()Lorg/apache/http/impl/client/cache/CacheConfig$Builder;
	at com.github.jsonldjava.utils.JsonUtils.createDefaultHttpClient(JsonUtils.java:333)
	at com.github.jsonldjava.utils.JsonUtils.getDefaultHttpClient(JsonUtils.java:323)
	at com.github.jsonldjava.core.DocumentLoader.getHttpClient(DocumentLoader.java:84)
	at com.github.jsonldjava.core.DocumentLoader.fromURL(DocumentLoader.java:59)
	at com.github.jsonldjava.core.DocumentLoader.loadDocument(DocumentLoader.java:29)
	at com.github.jsonldjava.core.Context.parse(Context.java:169)
	at com.github.jsonldjava.core.Context.parse(Context.java:252)
	at com.github.jsonldjava.core.JsonLdApi.expand(JsonLdApi.java:534)
	at com.github.jsonldjava.core.JsonLdApi.expand(JsonLdApi.java:981)
	at com.github.jsonldjava.core.JsonLdProcessor.expand(JsonLdProcessor.java:146)
	at com.github.jsonldjava.core.JsonLdProcessor.toRDF(JsonLdProcessor.java:482)
	at org.apache.jena.riot.lang.JsonLDReader.read$(JsonLDReader.java:143)
	at org.apache.jena.riot.lang.JsonLDReader.read(JsonLDReader.java:64)

This is caused by a newer JSONLD-Java 0.8.2 now depending on

		<httpclient.version>4.5.1</httpclient.version>
		<httpcore.version>4.4.4</httpcore.version>

while we explicitly depend on a much older version:

    <!-- These are connected because solr4j depends on httpclient as well -->
    <ver.httpclient>4.2.6</ver.httpclient>
    <ver.httpcore>4.2.5</ver.httpcore>

Issue JENA-576 discusses why HTTPClient was not upgraded.

I suggest we try again to upgrade HTTPClient, even if this means also a newer Solr.

A workaround would be to have an initialization to set JsonUtils.setDefaultClient() with our own instance - however that would break JSON-LD Context JAR caching which I know we use in Taverna to avoid network traffic.

As JSON-LD with external @context - e.g. with schema.org, is the primary way to use JSON-LD, then I think this should be a blocker for 3.1.0

Issue Links

• is related to: JENA-1178 JSON-LD https @contexts does not work
• relates to: JENA-576 Upgrade Apache HTTP Client to 4.3