| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * 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.android.statementservice.retriever; |
| |
| import android.util.JsonReader; |
| |
| import org.json.JSONArray; |
| import org.json.JSONException; |
| import org.json.JSONObject; |
| |
| import java.io.IOException; |
| import java.io.StringReader; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Utility class that parses JSON-formatted statements. |
| */ |
| /* package private */ final class StatementParser { |
| |
| private static final String FIELD_NOT_STRING_FORMAT_STRING = "Expected %s to be string."; |
| private static final String FIELD_NOT_ARRAY_FORMAT_STRING = "Expected %s to be array."; |
| |
| /** |
| * Parses a JSON array of statements. |
| */ |
| static ParsedStatement parseStatementList(String statementList, AbstractAsset source) |
| throws JSONException, IOException { |
| List<Statement> statements = new ArrayList<Statement>(); |
| List<String> delegates = new ArrayList<String>(); |
| |
| JsonReader reader = new JsonReader(new StringReader(statementList)); |
| reader.setLenient(false); |
| |
| reader.beginArray(); |
| while (reader.hasNext()) { |
| ParsedStatement result; |
| try { |
| result = parseStatement(reader, source); |
| } catch (AssociationServiceException e) { |
| // The element in the array is well formatted Json but not a well-formed Statement. |
| continue; |
| } |
| statements.addAll(result.getStatements()); |
| delegates.addAll(result.getDelegates()); |
| } |
| reader.endArray(); |
| |
| return new ParsedStatement(statements, delegates); |
| } |
| |
| /** |
| * Parses a single JSON statement. |
| */ |
| static ParsedStatement parseStatement(String statementString, AbstractAsset source) |
| throws AssociationServiceException, IOException, JSONException { |
| JsonReader reader = new JsonReader(new StringReader(statementString)); |
| reader.setLenient(false); |
| return parseStatement(reader, source); |
| } |
| |
| /** |
| * Parses a single JSON statement. This method guarantees that exactly one JSON object |
| * will be consumed. |
| */ |
| static ParsedStatement parseStatement(JsonReader reader, AbstractAsset source) |
| throws JSONException, AssociationServiceException, IOException { |
| List<Statement> statements = new ArrayList<Statement>(); |
| List<String> delegates = new ArrayList<String>(); |
| |
| JSONObject statement = JsonParser.parse(reader); |
| |
| if (statement.optString(Utils.DELEGATE_FIELD_DELEGATE, null) != null) { |
| delegates.add(statement.optString(Utils.DELEGATE_FIELD_DELEGATE)); |
| } else { |
| JSONObject targetObject = statement.optJSONObject(Utils.ASSET_DESCRIPTOR_FIELD_TARGET); |
| if (targetObject == null) { |
| throw new AssociationServiceException(String.format( |
| FIELD_NOT_STRING_FORMAT_STRING, Utils.ASSET_DESCRIPTOR_FIELD_TARGET)); |
| } |
| |
| JSONArray relations = statement.optJSONArray(Utils.ASSET_DESCRIPTOR_FIELD_RELATION); |
| if (relations == null) { |
| throw new AssociationServiceException(String.format( |
| FIELD_NOT_ARRAY_FORMAT_STRING, Utils.ASSET_DESCRIPTOR_FIELD_RELATION)); |
| } |
| |
| AbstractAsset target = AssetFactory.create(targetObject); |
| for (int i = 0; i < relations.length(); i++) { |
| statements.add(Statement |
| .create(source, target, Relation.create(relations.getString(i)))); |
| } |
| } |
| |
| return new ParsedStatement(statements, delegates); |
| } |
| } |