SchemaValidator.java

package de.zalando.toga.validator;

import java.io.File;
import java.io.IOException;

import com.fasterxml.jackson.databind.JsonNode;
import com.github.fge.jackson.JsonLoader;
import com.github.fge.jsonschema.core.exceptions.ProcessingException;
import com.github.fge.jsonschema.core.report.ProcessingReport;
import com.github.fge.jsonschema.main.JsonSchema;
import com.github.fge.jsonschema.main.JsonSchemaFactory;

import static com.github.fge.jackson.JsonLoader.fromFile;
import static com.github.fge.jackson.JsonLoader.fromString;

public class SchemaValidator {

    private JsonSchema schema;

    public void loadSchema(File schemaLocation) {
        try {
            JsonNode schemaNode = fromFile(schemaLocation);
            schema = JsonSchemaFactory.byDefault().getJsonSchema(schemaNode);
        } catch (IOException | ProcessingException e) {
            throw new RuntimeException("Error loading schema", e);
        }

    }

    public ProcessingReport validate(String input) {
        if (schema == null) {
            throw new IllegalStateException("Tried to validate without schema.");
        }

        try {
            final JsonNode dataNode = fromString(input);

            return schema.validate(dataNode);
        } catch (IOException | ProcessingException e) {
            throw new RuntimeException("Exception while validating.", e);
        }
    }
}