Java tutorial
/* * Wikidata Vandalism Detector 2016 (WDVD-2016) * * Copyright (c) 2016 Stefan Heindorf, Martin Potthast, Benno Stein, Gregor Engels * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ package de.upb.wdqa.wdvd.datamodel.oldjson.jackson.deserializers; import java.io.IOException; import java.util.LinkedHashMap; import java.util.List; import org.apache.log4j.Logger; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.core.JsonToken; import com.fasterxml.jackson.core.ObjectCodec; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.JsonDeserializer; import de.upb.wdqa.wdvd.datamodel.oldjson.jackson.OldAliasList; /** * * It implements a workaround to cope with empty aliases being represented as * <code>"aliases":[]</code> despite its declaration as map and not as list or * array. * */ public class OldAliasesDeserializer extends JsonDeserializer<LinkedHashMap<String, List<String>>> { private static final Logger logger = Logger.getLogger(OldAliasesDeserializer.class); @Override public LinkedHashMap<String, List<String>> deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException { LinkedHashMap<String, List<String>> result = new LinkedHashMap<String, List<String>>(); // Is the alias broken, i.e., it starts with '[' if (jp.getCurrentToken().equals(JsonToken.START_ARRAY)) { jp.nextToken(); if (!jp.getCurrentToken().equals(JsonToken.END_ARRAY)) { logger.warn("Token " + JsonToken.END_ARRAY + " expected"); } } else { ObjectCodec mapper = jp.getCodec(); result = mapper.readValue(jp, new TypeReference<LinkedHashMap<String, OldAliasList>>() { }); } return result; } }