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.oo.ChannelProxy; import org.apache.ode.jacob.soup.CommChannel; import org.apache.ode.jacob.soup.jackson.JacksonExecutionQueueImpl.ExecutionQueueImplSerializer; import org.apache.ode.jacob.vpu.ChannelFactory; import com.fasterxml.jackson.core.JsonGenerationException; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.databind.SerializerProvider; import com.fasterxml.jackson.databind.jsontype.TypeSerializer; import com.fasterxml.jackson.databind.jsontype.impl.ClassNameIdResolver; import com.fasterxml.jackson.databind.ser.std.StdSerializer; /** * Jackson serializer for Channel Proxies. * Serializes only channel id and channel type. Also keeps a * list of serialized channels, which is needed for the garbage * collection of unused channels in the ExecutionQueue serializer. * * @author Tammo van Lessen * */ public class ChannelProxySerializer extends StdSerializer<ChannelProxy> { private final ExecutionQueueImplSerializer executionQueueImplSerializer; protected ChannelProxySerializer(ExecutionQueueImplSerializer executionQueueImplSerializer) { super(ChannelProxy.class); this.executionQueueImplSerializer = executionQueueImplSerializer; } @Override public void serialize(ChannelProxy value, JsonGenerator jgen, SerializerProvider provider) throws IOException, JsonGenerationException { jgen.writeStartObject(); serializeContents(value, jgen, provider); jgen.writeEndObject(); } @Override public void serializeWithType(ChannelProxy value, JsonGenerator jgen, SerializerProvider provider, TypeSerializer typeSer) throws IOException, JsonGenerationException { typeSer.writeTypePrefixForObject(value, jgen); serializeContents(value, jgen, provider); typeSer.writeTypeSuffixForObject(value, jgen); } private void serializeContents(ChannelProxy value, JsonGenerator jgen, SerializerProvider provider) throws JsonGenerationException, IOException { CommChannel commChannel = ChannelFactory.getBackend((Channel) value); ClassNameIdResolver idResolver = new ClassNameIdResolver(provider.constructType(commChannel.getType()), provider.getTypeFactory()); Integer cid = (Integer) commChannel.getId(); jgen.writeStringField("channelType", idResolver.idFromBaseType()); jgen.writeNumberField("channelId", cid); // save channel id for garbage collection executionQueueImplSerializer.markChannelUsed(cid); } }