Java tutorial
/* * Copyright 2016 Netflix, Inc. * * Licensed 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 com.netflix.discovery.converters.jackson.serializer; import java.io.IOException; import java.util.Collections; import java.util.Map; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.SerializerProvider; import com.fasterxml.jackson.databind.ser.BeanSerializer; import com.fasterxml.jackson.databind.ser.std.BeanSerializerBase; import com.netflix.appinfo.InstanceInfo; import com.netflix.appinfo.InstanceInfo.PortType; /** * Custom bean serializer to deal with legacy port layout (check {@link InstanceInfo.PortWrapper} for more information). */ public class InstanceInfoJsonBeanSerializer extends BeanSerializer { private static final Map<String, String> EMPTY_MAP = Collections.singletonMap("@class", "java.util.Collections$EmptyMap"); /** * As root mapper is wrapping values, we need a dedicated instance for map serialization. */ private final ObjectMapper stringMapObjectMapper = new ObjectMapper(); private final boolean compactMode; public InstanceInfoJsonBeanSerializer(BeanSerializerBase src, boolean compactMode) { super(src); this.compactMode = compactMode; } @Override protected void serializeFields(Object bean, JsonGenerator jgen0, SerializerProvider provider) throws IOException { super.serializeFields(bean, jgen0, provider); InstanceInfo instanceInfo = (InstanceInfo) bean; jgen0.writeFieldName("port"); jgen0.writeStartObject(); jgen0.writeNumberField("$", instanceInfo.getPort()); jgen0.writeStringField("@enabled", Boolean.toString(instanceInfo.isPortEnabled(PortType.UNSECURE))); jgen0.writeEndObject(); jgen0.writeFieldName("securePort"); jgen0.writeStartObject(); jgen0.writeNumberField("$", instanceInfo.getSecurePort()); jgen0.writeStringField("@enabled", Boolean.toString(instanceInfo.isPortEnabled(PortType.SECURE))); jgen0.writeEndObject(); // Save @class field for backward compatibility. Remove once all clients are migrated to the new codec if (!compactMode) { jgen0.writeFieldName("metadata"); if (instanceInfo.getMetadata() == null || instanceInfo.getMetadata().isEmpty()) { stringMapObjectMapper.writeValue(jgen0, EMPTY_MAP); } else { stringMapObjectMapper.writeValue(jgen0, instanceInfo.getMetadata()); } } } }