Java tutorial
/* * (c) Copyright Reserved EVRYTHNG Limited 2016. All rights reserved. * Use of this material is subject to license. * Copying and unauthorised use of this material strictly prohibited. */ package com.evrythng.java.wrapper.mapping; import com.evrythng.java.wrapper.util.JSONUtils; import com.evrythng.thng.resource.model.store.PseudoRandomShortIdTemplate; import com.evrythng.thng.resource.model.store.SequentialShortIdTemplate; import com.evrythng.thng.resource.model.store.ShortIdTemplate; import com.evrythng.thng.resource.model.store.ThngIdShortIdTemplate; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import java.io.IOException; public class ShortIdTemplateDeserializer extends Deserializer<ShortIdTemplate> { private static final long serialVersionUID = 6416974680823486697L; public ShortIdTemplateDeserializer() { super(ShortIdTemplate.class); } @Override public ShortIdTemplate deserialize(final JsonParser jp, final DeserializationContext ctx) throws IOException { ObjectMapper mapper = JSONUtils.OBJECT_MAPPER; JsonNode node = mapper.readTree(jp); JsonNode typeNode = node.get(ShortIdTemplate.FIELD_TYPE); if (typeNode == null) { throw new JsonMappingException("Cannot deserialize task on batch without type field"); } String typeRaw = getFieldValue(typeNode); Class<? extends ShortIdTemplate> subtypeClass = classForType( ShortIdTemplate.Type.valueOf(typeRaw.toUpperCase())); return mapper.readValue(node.toString(), subtypeClass); } private Class<? extends ShortIdTemplate> classForType(final ShortIdTemplate.Type type) { switch (type) { case THNG_ID: return ThngIdShortIdTemplate.class; case PSEUDO_RANDOM: return PseudoRandomShortIdTemplate.class; case SEQUENTIAL: return SequentialShortIdTemplate.class; } throw new IllegalArgumentException("Unsupported short id template type: " + type); } }