edu.artic.geneva.sync.UpdateProcessor.java Source code

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Here is the source code for edu.artic.geneva.sync.UpdateProcessor.java

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/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package edu.artic.geneva.sync;

import static com.github.jsonldjava.core.JsonLdProcessor.expand;
import static com.github.jsonldjava.core.JsonLdProcessor.toRDF;
import static com.github.jsonldjava.utils.JsonUtils.fromString;
import static edu.artic.geneva.sync.GenevaSyncHeaders.GENEVA_JSON_LD_DOCUMENT;
import static java.util.stream.Collectors.toList;

import java.io.IOException;
import java.util.List;
import java.util.Map;

import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.apache.camel.Processor;
import org.apache.camel.RuntimeCamelException;

import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonParseException;
import com.github.jsonldjava.core.JsonLdError;
import com.github.jsonldjava.core.JsonLdOptions;

/**
 * Represents a processor for translating a JSON document into a SparQL update query.
 *
 * @author Aaron Coburn
 */
class UpdateProcessor implements Processor {

    public void process(final Exchange exchange) throws IOException {

        final Message in = exchange.getIn();

        try {

            final JsonLdOptions opts = new JsonLdOptions("") {
                {
                    format = "application/nquads";
                }
            };

            final Object doc = fromString(in.getHeader(GENEVA_JSON_LD_DOCUMENT, String.class));
            final List<Object> expanded = expand(doc);
            final Map<String, Object> map = (Map<String, Object>) expanded.get(0);
            final Object res = toRDF(doc, null, opts);
            final StringBuilder sb = new StringBuilder("DELETE WHERE {");

            map.remove("@id");
            map.remove("@context");
            if (map.containsKey("@type")) {
                if (map.get("@type") instanceof List) {
                    for (final Object t : (List) map.get("@type")) {
                        sb.append("<> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <" + (String) t + "> . \n");
                    }
                } else if (map.get("@type") instanceof String) {
                    sb.append("<> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <" + (String) map.get("@type")
                            + "> .\n");
                }
            }
            final List<String> preds = map.entrySet().stream().map(e -> e.getKey()).filter(e -> !e.startsWith("@"))
                    .collect(toList());

            for (int i = 0; i < preds.size(); i++) {
                sb.append("<> <" + preds.get(i) + "> ?o" + i + " .\n");
            }
            sb.append("};\n");

            sb.append("INSERT DATA {");
            sb.append(res);
            sb.append("}");

            in.setBody(sb.toString());

        } catch (final JsonLdError ex) {
            throw new RuntimeCamelException("Error expanding JSON-LD", ex);
        } catch (final JsonParseException ex) {
            throw new RuntimeCamelException("Error parsing JSON", ex);
        } catch (final JsonGenerationException ex) {
            throw new RuntimeCamelException("Error generating JSON", ex);
        }
    }
}