donal donal - 4 years ago 432
Java Question

java json schema validation relative path not working (URI not found)

I am looking at the 2.2.6 version of the validator code from github.
I have not changed any code from the repo "https://github.com/fge/json-schema-validator.git"

I am unable to get example 1 running when i test it against my json schema that references a second schema file (I can get it working when I resort to a hardcoded URI).

I have simply repointed the "com.github.fge.jsonschema.examples.Example1.java" to use my teams json schema and json files.
I have built the project and copied my json schema files into "json-schema-validator\bin\com\github\fge\jsonschema\examples" (All in the same folder, similar to fstab examples)

A section of the top level is attached,



},
"MovingWindow": {
"description": "Is this an moving window measure?",
"type": "boolean"
}
},
"minItems": 1,
"uniqueItems": true
},
"RealTimeProfile": {
"$ref": "rtp.json#"
}
},
"required": [
"MeasureTemplateId",
"MeasureInstanceId",





but I am unable to get the reading of the lower level, 2nd schema file ("rtp.json") to be recognised & work correctly.
I am seeing the below error:

Exception in thread "main" com.github.fge.jsonschema.core.exceptions.ProcessingException: fatal: URI "rtp.json#" is not absolute
level: "fatal"
uri: "rtp.json#"

Snippet of my code:



File jsonFile = new File("CumulativeCountBad.json");
File jsonSchemaFile = new File("main.json");


JsonNode good = JsonLoader.fromFile(jsonFile);
JsonNode mainSchema = JsonLoader.fromFile(jsonSchemaFile);

final JsonSchemaFactory factory = JsonSchemaFactory.byDefault();

final JsonSchema schema = factory.getJsonSchema(mainSchema);

ProcessingReport report;

report = schema.validate(good);
System.out.println("good: " + report);





My issue seems similar to the following issue but i don't seem to be able to gett the thing running when i set the reference to:
"$ref": "rtp.json#"

https://github.com/fge/json-schema-validator/issues/94

Any help appreciated.
PS - I am a java newbie, apologies if there is something obvious that i have ommited
Thanks

Answer Source

The problem is that you load the JSON then turn it into a schema. And your schema does not have an absolute URI in "id". So, it cannot work.

You want to use an absolute URI to load them. Since you originally use a File (note, with Java 7+ you really want to use java.nio.file instead), you can obtain an absolute URI to it with:

final File jsonSchemaFile = new File("main.json");
final URI uri = jsonSchemaFile.toURI();

You then load the schema with:

final JsonSchema schema = factory.getJsonSchema(uri.toString());
Recommended from our users: Dynamic Network Monitoring from WhatsUp Gold from IPSwitch. Free Download