---
tags: ShEx, JVM, API
---
# ShEx Validation JVM API

Tracking issues:
* [iovka/shex-java](https://github.com/iovka/shex-java/issues/27)
* [weso/shex-s](https://github.com/weso/shex-s/issues/224)
* [Apache Jena](https://issues.apache.org/jira/browse/JENA-2115)

Goal: common API for invoking basic validation function across all JVM ShEx validators.

The input parameters:
1. ShapeMap or node/shape pair
2. ShEx schema
3. getNeighborhood implementation

can be split across multiple operations:
1. construct validator
2. execute validator

These can be tuned to optimize for:
1. validate different data with same schema
2. validate data with different schema

2 seems a bit unlikely so propose to aim for 1. That implies passing the schema in with the validator constructor, so it can index the schema for efficient validation.

abstract class Validator {
  Validator(ShExSchema schema);
  ResultShapeMap validate(FixedShapeMap pairs, NeighborhoodDB db);
}

interface NeighborhoodDB {
  ArrayList<Triple> getNeighborhood(RdfNode);
}

// https://shexspec.github.io/shape-map/
interface FixedShapeMap {
  RdfNode node;
  ShExShape shape;
  Enum { conformant, nonconformant } status;
}
interface ResultShapeMap extends FixedShapeMap {
  string reason;
  AppInfo appinfo;
}

abstract class AppInfo {}

The shex.js FixedShapeMap can include a status which allows you to signal an error only when you get a different status. Not sure that's great, but it's handy.

## Existing APIs:

### shex-java

### shex-s

### Jena