Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 org.apache.ode.jacob.soup.jackson; import java.io.IOException; import org.apache.ode.jacob.oo.Channel; import org.apache.ode.jacob.soup.CommChannel; import org.apache.ode.jacob.vpu.ChannelFactory; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.core.JsonToken; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.deser.std.StdDeserializer; /** * Jackson deserializer for Channels. * Creates ChannelProxy instances based on channel id and channel type. * * @author Tammo van Lessen * */ public class ChannelProxyDeserializer extends StdDeserializer<Channel> { private static final long serialVersionUID = 1L; public ChannelProxyDeserializer() { super(Channel.class); } @Override public Channel deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException { String type = null; int id = -1; while (jp.nextToken() != JsonToken.END_OBJECT) { String fieldname = jp.getCurrentName(); if (jp.getCurrentToken() == JsonToken.FIELD_NAME) { // if we're not already on the field, advance by one. jp.nextToken(); } if ("channelType".equals(fieldname)) { type = jp.getText(); } else if ("channelId".equals(fieldname)) { id = jp.getIntValue(); } } if (type == null) { throw ctxt.mappingException(Channel.class); } if (id < 0) { throw ctxt.mappingException(Channel.class); } try { CommChannel cchannel = new CommChannel(ctxt.findClass(type)); cchannel.setId(id); return (Channel) ChannelFactory.createChannel(cchannel, cchannel.getType()); } catch (ClassNotFoundException e) { throw ctxt.instantiationException(Channel.class, e); } } }