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.qpid.disttest.json; import java.lang.reflect.Type; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import org.apache.qpid.disttest.client.property.GeneratedPropertyValue; import org.apache.qpid.disttest.client.property.PropertyValue; import org.apache.qpid.disttest.client.property.PropertyValueFactory; import org.apache.qpid.disttest.client.property.SimplePropertyValue; import com.google.gson.JsonArray; import com.google.gson.JsonDeserializationContext; import com.google.gson.JsonDeserializer; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonParseException; import com.google.gson.JsonPrimitive; import com.google.gson.JsonSerializationContext; import com.google.gson.JsonSerializer; public class PropertyValueAdapter implements JsonDeserializer<PropertyValue>, JsonSerializer<PropertyValue> { private static final String DEF_FIELD = "@def"; private PropertyValueFactory _factory = new PropertyValueFactory(); @Override public PropertyValue deserialize(JsonElement json, Type type, JsonDeserializationContext context) throws JsonParseException { if (json.isJsonNull()) { return null; } else if (json.isJsonPrimitive()) { Object result = null; JsonPrimitive primitive = json.getAsJsonPrimitive(); if (primitive.isString()) { result = primitive.getAsString(); } else if (primitive.isNumber()) { String asString = primitive.getAsString(); if (asString.indexOf('.') != -1 || asString.indexOf('e') != -1) { result = primitive.getAsDouble(); } else { result = primitive.getAsLong(); } } else if (primitive.isBoolean()) { result = primitive.getAsBoolean(); } else { throw new JsonParseException("Unsupported primitive value " + primitive); } return new SimplePropertyValue(result); } else if (json.isJsonArray()) { JsonArray array = json.getAsJsonArray(); List<Object> result = new ArrayList<Object>(array.size()); for (JsonElement element : array) { result.add(context.deserialize(element, Object.class)); } return new SimplePropertyValue(result); } else if (json.isJsonObject()) { JsonObject object = json.getAsJsonObject(); JsonElement defElement = object.getAsJsonPrimitive(DEF_FIELD); Class<?> classInstance = null; if (defElement != null) { try { classInstance = _factory.getPropertyValueClass(defElement.getAsString()); } catch (ClassNotFoundException e) { // ignore } } if (classInstance == null) { Map<String, Object> result = new HashMap<String, Object>(); for (Map.Entry<String, JsonElement> entry : object.entrySet()) { Object value = context.deserialize(entry.getValue(), Object.class); result.put(entry.getKey(), value); } return new SimplePropertyValue(result); } else { return context.deserialize(json, classInstance); } } else { throw new JsonParseException("Unsupported JSON type " + json); } } @Override public JsonElement serialize(PropertyValue src, Type typeOfSrc, JsonSerializationContext context) { if (src instanceof GeneratedPropertyValue) { JsonObject object = (JsonObject) context.serialize(src, Object.class); object.addProperty(DEF_FIELD, ((GeneratedPropertyValue) src).getDefinition()); return object; } else { return context.serialize(src.getValue(), Object.class); } } }