be.ordina.msdashboard.aggregators.index.IndexToNodeConverter.java Source code

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Here is the source code for be.ordina.msdashboard.aggregators.index.IndexToNodeConverter.java

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/*
 * Copyright 2012-2016 the original author or authors.
 *
 * 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 be.ordina.msdashboard.aggregators.index;

import be.ordina.msdashboard.model.Node;
import be.ordina.msdashboard.model.NodeBuilder;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import rx.Observable;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * @author Andreas Evers
 * @author Tim Ysewyn
 */
public class IndexToNodeConverter {

    private static final Logger logger = LoggerFactory.getLogger(IndexToNodeConverter.class);

    private static final String LINKS = "_links";
    private static final String CURIES = "curies";
    private static final String HREF = "href";
    private static final String CURIE_NAME = "name";
    private static final String RESOURCE = "RESOURCE";
    private static final String UP = "UP";

    public Observable<Node> convert(String serviceId, String serviceUri, String source) {
        try {
            JSONObject index = new JSONObject(source);

            if (index.has(LINKS)) {
                return Observable.from(getNodesFromJSON(serviceId, serviceUri, index));
            } else {
                logger.error("Index deserialization fails because no HAL _links was found at the root");
                return Observable.empty();
            }
        } catch (JSONException je) {
            logger.error("Could not parse JSON: {}", je);
            return Observable.empty();
        }
    }

    @SuppressWarnings("unchecked")
    private List<Node> getNodesFromJSON(String serviceId, String serviceUri, JSONObject index) {
        List<Node> nodes = new ArrayList<>();

        NodeBuilder serviceNode = NodeBuilder.node().withId(serviceId).withLane(2);

        JSONObject links = index.getJSONObject(LINKS);
        final boolean hasCuries = links.has(CURIES);

        Set<String> keyset = new HashSet<>(links.keySet());

        keyset.stream().filter(linkKey -> !CURIES.equals(linkKey)).forEach(linkKey -> {
            serviceNode.withLinkedFromNodeId(linkKey);

            JSONObject link = links.getJSONObject(linkKey);

            Node linkedNode = convertLinkToNodes(linkKey, link, serviceId);
            if (hasCuries) {
                String docs = resolveDocs(linkKey, links.getJSONArray(CURIES), serviceUri);

                if (docs != null) {
                    linkedNode.addDetail("docs", docs);
                }
            }

            nodes.add(linkedNode);
        });

        nodes.add(0, serviceNode.build());

        return nodes;
    }

    private Node convertLinkToNodes(String linkKey, JSONObject link, String linkToServiceId) {
        return NodeBuilder.node().withId(linkKey).withLane(1).withLinkedToNodeId(linkToServiceId)
                .withDetail("url", link.getString(HREF)).withDetail("type", RESOURCE).withDetail("status", UP)
                .build();
    }

    private String resolveDocs(String linkKey, JSONArray curies, String serviceUri) {
        String namespace = linkKey.substring(0, linkKey.indexOf(":"));

        for (int i = 0; i < curies.length();) {
            JSONObject curie = curies.getJSONObject(i);

            if (curie.has(CURIE_NAME) && curie.getString(CURIE_NAME).equals(namespace)) {
                return serviceUri
                        + curie.getString(HREF).replace("{rel}", linkKey.substring(linkKey.indexOf(":") + 1));
            }

            ++i;
        }

        return null;
    }
}