| /* |
| * 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.rya.api.domain; |
| |
| import java.io.UnsupportedEncodingException; |
| import java.lang.reflect.Type; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import org.apache.rya.api.persist.RdfDAOException; |
| import org.eclipse.rdf4j.model.impl.SimpleValueFactory; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.reflect.TypeToken; |
| import com.google.gson.Gson; |
| import com.google.gson.GsonBuilder; |
| 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 StatementMetadata { |
| |
| private static Gson gson = new GsonBuilder().enableComplexMapKeySerialization() |
| .registerTypeHierarchyAdapter(RyaType.class, new RyaTypeAdapter()).create(); |
| public static StatementMetadata EMPTY_METADATA = new StatementMetadata(); |
| |
| private Map<RyaIRI, RyaType> metadataMap = new HashMap<>(); |
| @SuppressWarnings("serial") |
| private Type type = new TypeToken<Map<RyaIRI, RyaType>>(){}.getType(); |
| |
| public StatementMetadata() {} |
| |
| public StatementMetadata(byte[] value) throws RdfDAOException { |
| try { |
| if (value == null) { |
| metadataMap = new HashMap<>(); |
| } else { |
| // try to convert back to a json string and then back to the |
| // map. |
| String metadataString = new String(value, "UTF8"); |
| metadataMap = gson.fromJson(metadataString, type); |
| if (metadataMap == null) { |
| metadataMap = new HashMap<>(); |
| } |
| } |
| } catch (UnsupportedEncodingException e) { |
| throw new RdfDAOException(e); |
| } |
| } |
| |
| public StatementMetadata(String statementMetadata) { |
| try { |
| metadataMap = gson.fromJson(statementMetadata, type); |
| } catch (Exception e) { |
| throw new RdfDAOException(e); |
| } |
| } |
| |
| public void addMetadata(RyaIRI key, RyaType value) { |
| metadataMap.put(key, value); |
| } |
| |
| public Map<RyaIRI, RyaType> getMetadata() { |
| return metadataMap; |
| } |
| |
| public String toString() { |
| return gson.toJson(metadataMap, type); |
| } |
| |
| public byte[] toBytes() { |
| // convert the map to a json string |
| if (metadataMap.isEmpty()) { |
| return null; |
| } |
| // TODO may want to cache this for performance reasons |
| try { |
| return toString().getBytes("UTF8"); |
| } catch (UnsupportedEncodingException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| public static class RyaTypeAdapter implements JsonSerializer<RyaType>, JsonDeserializer<RyaType> { |
| @Override |
| public JsonElement serialize(RyaType src, Type typeOfSrc, JsonSerializationContext context) { |
| JsonObject result = new JsonObject(); |
| result.add("type", new JsonPrimitive(src.getClass().getName())); |
| |
| StringBuilder builder = new StringBuilder(); |
| builder.append(src.getData()).append("\u0000").append(src.getDataType().toString()); |
| result.add("properties", new JsonPrimitive(builder.toString())); |
| |
| return result; |
| } |
| |
| @Override |
| public RyaType deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) |
| throws JsonParseException { |
| JsonObject jsonObject = json.getAsJsonObject(); |
| String type = jsonObject.get("type").getAsString(); |
| JsonElement element = jsonObject.get("properties"); |
| String[] array = element.getAsJsonPrimitive().getAsString().split("\u0000"); |
| Preconditions.checkArgument(array.length == 2); |
| |
| if(type.equals(RyaIRI.class.getName())){ |
| return new RyaIRI(array[0]); |
| } else if(type.equals(RyaType.class.getName())){ |
| RyaType ryaType = new RyaType(SimpleValueFactory.getInstance().createIRI(array[1]), array[0]); |
| return ryaType; |
| } else { |
| throw new IllegalArgumentException("Unparseable RyaType."); |
| } |
| } |
| } |
| |
| } |