JsonHandler.java

package com.github.bjuvensjo.rsimulator.core.handler.regexp;

import com.google.inject.Singleton;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.ObjectMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Iterator;
import java.util.Map.Entry;

/**
 * JsonHandler is a regular expression handler for json (.json).
 *
 * @author Magnus Bjuvensjö
 * @see AbstractHandler
 */
@Singleton
public class JsonHandler extends AbstractHandler {
    private static final String EXTENSION = "json";
    private Logger log = LoggerFactory.getLogger(JsonHandler.class);
    private ObjectMapper mapper;

    public JsonHandler() {
        super();
        mapper = new ObjectMapper();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected String escape(String request, boolean isCandidate) {
        String result = request;
        if (isCandidate && request != null && !"".equals(request)) {
            try {
                StringBuilder sb = new StringBuilder();
                JsonNode rootNode = mapper.readValue(request, JsonNode.class);
                escape(sb, rootNode, null);
                result = sb.toString();
            } catch (Exception e) {
                log.error(null, e);
            }
        }
        return result;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected String format(String request) {
        String result = request;
        if (request != null && !"".equals(request)) {
            try {
                JsonNode rootNode = mapper.readValue(request, JsonNode.class);
                result = mapper.writeValueAsString(rootNode);
            } catch (Exception e) {
                log.error(null, e);
            }
        }
        return result;
    }

    private void escape(StringBuilder sb, JsonNode node, String name) {
        if (node.isArray()) {
            sb.append("\\[");
            Iterator<JsonNode> iterator = node.iterator();
            int n = 0;
            while (iterator.hasNext()) {
                if (n > 0) {
                    sb.append(",");
                }
                n++;
                escape(sb, iterator.next(), null);
            }
            sb.append("\\]");
        } else if (node.isObject()) {
            sb.append("\\{");
            Iterator<Entry<String, JsonNode>> fields = node.getFields();
            int n = 0;
            while (fields.hasNext()) {
                if (n > 0) {
                    sb.append(",");
                }
                n++;
                Entry<String, JsonNode> field = fields.next();
                escape(sb, field.getValue(), field.getKey());
            }
            sb.append("\\}");
        } else {
            sb.append("\"").append(name).append("\":").append(node.toString());
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected String getExtension() {
        return EXTENSION;
    }
}