/* * Copyright 2013 Nokia Corporation * * 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.nokia.util.avro.types; import org.codehaus.jackson.annotate.JsonValue; import java.util.HashSet; import java.util.List; import java.util.Set; /** * Class which represents an Avro union type. * http://avro.apache.org/docs/current/spec.html#Unions * * @author Ben Fagin (Nokia) * @version 01-12-2012 */ public class AvroUnion extends AvroType { public final AvroType[] types; public AvroUnion(AvroType...types) { if (types != null) { // Set<AvroType> typeSet = mergeUnions(types); // this.types = typeSet.toArray(new AvroType[typeSet.size()]); this.types = types; } else { this.types = new AvroType[]{}; } defaultValue = _getDefaultValue(); } public AvroUnion(List<AvroType> types) { this(types.toArray(new AvroType[types.size()])); } @JsonValue private AvroType[] jsonValue() { return types; } @Override public Set<String> getDependencies() { Set<String> dependencies = new HashSet<String>(); for (AvroType type : types) { dependencies.addAll(type.getDependencies()); } return dependencies; } /** * From the avro spec: * <pre> * Default values for union fields correspond to the first schema in the union. * </pre> */ private String _getDefaultValue() { if (types.length == 0) { return null; } else { return types[0].getDefaultValue(); } } // this is a bit hackish, but nested unions are not allowed // better would be to prevent them from being created in the first place private Set<AvroType> mergeUnions(AvroType...types) { Set<AvroType> retval = new HashSet<AvroType>(); Set<String> seen = new HashSet<String>(); for (AvroType type : types) { if (type instanceof AvroUnion) { retval.addAll(mergeUnions(((AvroUnion) type).types)); } else { if (type instanceof AvroType) retval.add(type); } } return retval; } }