/* * Copyright (c) 2017, 2018, Salesforce.com, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the * following conditions are met: * * * Redistributions of source code must retain the above copyright notice, this list of conditions and the following * disclaimer. * * * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided with the distribution. * * * Neither the name of Salesforce.com nor the names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package com.salesforce.storm.spout.sideline.persistence; import com.google.common.base.Preconditions; 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.JsonSerializationContext; import com.google.gson.JsonSerializer; import com.salesforce.storm.spout.dynamic.filter.FilterChainStep; import com.salesforce.storm.spout.sideline.config.SidelineConfig; import java.lang.reflect.Type; import java.util.Map; /** * Gson handler for creating FilterChainStep instances. * @param <T> object type for serializing and deserializing, should be a FilterChainStep implementation. */ public class FilterChainStepSerializer<T extends FilterChainStep> implements JsonDeserializer<T>, JsonSerializer<T> { /** * Configuration from the spout. */ private final Map<String, Object> config; /** * Gson handler for creating FilterChainStep instances. * @param config configuration from the spout. */ public FilterChainStepSerializer(final Map<String, Object> config) { this.config = config; } @Override public JsonElement serialize(T obj, Type typeOfObj, JsonSerializationContext context) { // Implement what is essentially the default serialization strategy here. // This might seem odd, but before I did this, when FilterChainStep's were nested they did not serialize correctly return context.serialize(obj); } @Override public T deserialize( final JsonElement jsonElement, final Type type, final JsonDeserializationContext deserializationContext ) throws JsonParseException { final JsonObject jsonObject = jsonElement.getAsJsonObject(); final Class<T> clazz = getClassInstance(); return deserializationContext.deserialize(jsonObject, clazz); } @SuppressWarnings("unchecked") private Class<T> getClassInstance() { @SuppressWarnings("unchecked") final String className = (String) config.get(SidelineConfig.FILTER_CHAIN_STEP_CLASS); Preconditions.checkArgument( className != null && !className.isEmpty(), "A valid class name must be specified for " + SidelineConfig.FILTER_CHAIN_STEP_CLASS ); try { return (Class<T>) Class.forName(className); } catch (ClassNotFoundException cnfe) { throw new JsonParseException(cnfe.getMessage()); } } }