Java tutorial
/** * Copyright (c) 2014, Sindice Limited. All Rights Reserved. * * This file is part of the SIREn 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.sindicetech.siren.demo.ncpr; import java.io.File; import java.io.FileReader; import java.io.IOException; import java.util.Iterator; import org.codehaus.jackson.JsonEncoding; import org.codehaus.jackson.JsonGenerator; import org.codehaus.jackson.JsonNode; import org.codehaus.jackson.map.ObjectMapper; import org.codehaus.jackson.node.ObjectNode; import com.google.common.io.LineReader; import com.sindicetech.siren.analysis.ExtendedJsonTokenizer; /** * This class convert the original NCPR JSON dataset into a JSON dataset with * explicit value datatypes. */ public class DatatypeConverter { private final ObjectMapper mapper; private final JsonGenerator generator; private final static String INPUT_FILE = "./src/example/json/ncpr.json"; private final static String OUTPUT_FILE = "./src/example/json/ncpr-with-datatypes.json"; public DatatypeConverter() throws IOException { this.mapper = new ObjectMapper(); generator = mapper.getJsonFactory().createJsonGenerator(new File(OUTPUT_FILE), JsonEncoding.UTF8); } public void process() throws IOException { final FileReader fileReader = new FileReader(new File(INPUT_FILE)); final LineReader reader = new LineReader(fileReader); try { JsonNode obj; String line; while ((line = reader.readLine()) != null) { obj = mapper.readTree(line); this.convertRatedOutputCurrent(obj); this.convertRatedOutputVoltage(obj); this.convertRatedOutputkW(obj); this.convertLatitude(obj); this.convertLongitude(obj); this.convertTetheredCable(obj); this.convertChargeMode(obj); this.convertDeviceControllerWebsite(obj); this.convertDeviceOwnerWebsite(obj); generator.writeTree(obj); generator.writeRaw('\n'); } } finally { fileReader.close(); } } private void convertRatedOutputkW(final JsonNode obj) { final Iterator<JsonNode> nodes = obj.path("Connector").iterator(); while (nodes.hasNext()) { final ObjectNode node = (ObjectNode) nodes.next(); final JsonNode current = node.path("RatedOutputkW"); if (!current.isMissingNode() && !current.isNull()) { final double value = Double.parseDouble(current.asText()); node.put("RatedOutputkW", value); } if (current.isNull()) { node.remove("RatedOutputkW"); } } } private void convertRatedOutputVoltage(final JsonNode obj) { final Iterator<JsonNode> nodes = obj.path("Connector").iterator(); while (nodes.hasNext()) { final ObjectNode node = (ObjectNode) nodes.next(); final JsonNode current = node.path("RatedOutputVoltage"); if (!current.isMissingNode() && !current.isNull()) { final int value = Integer.parseInt(current.asText()); node.put("RatedOutputVoltage", value); } if (current.isNull()) { node.remove("RatedOutputVoltage"); } } } private void convertRatedOutputCurrent(final JsonNode obj) { final Iterator<JsonNode> nodes = obj.path("Connector").iterator(); while (nodes.hasNext()) { final ObjectNode node = (ObjectNode) nodes.next(); final JsonNode current = node.path("RatedOutputCurrent"); if (!current.isMissingNode() && !current.isNull()) { final int value = Integer.parseInt(current.asText()); node.put("RatedOutputCurrent", value); } if (current.isNull()) { node.remove("RatedOutputCurrent"); } } } private void convertTetheredCable(final JsonNode obj) { final Iterator<JsonNode> nodes = obj.path("Connector").iterator(); while (nodes.hasNext()) { final ObjectNode node = (ObjectNode) nodes.next(); final JsonNode current = node.path("TetheredCable"); if (!current.isMissingNode() && !current.isNull()) { final int value = Integer.parseInt(current.asText()); node.put("TetheredCable", value); } if (current.isNull()) { node.remove("TetheredCable"); } } } private void convertChargeMode(final JsonNode obj) { final Iterator<JsonNode> nodes = obj.path("Connector").iterator(); while (nodes.hasNext()) { final ObjectNode node = (ObjectNode) nodes.next(); final JsonNode current = node.path("ChargeMode"); if (!current.isMissingNode() && !current.isNull()) { final int value = Integer.parseInt(current.asText()); node.put("ChargeMode", value); } if (current.isNull()) { node.remove("ChargeMode"); } } } private void convertLatitude(final JsonNode obj) { final ObjectNode node = (ObjectNode) obj.path("ChargeDeviceLocation"); final JsonNode current = node.path("Latitude"); if (!current.isMissingNode() && !current.isNull()) { final double value = Double.parseDouble(current.asText()); node.put("Latitude", value); } if (current.isNull()) { node.remove("Latitude"); } } private void convertLongitude(final JsonNode obj) { final ObjectNode node = (ObjectNode) obj.path("ChargeDeviceLocation"); final JsonNode current = node.path("Longitude"); if (!current.isMissingNode() && !current.isNull()) { final double value = Double.parseDouble(current.asText()); node.put("Longitude", value); } if (current.isNull()) { node.remove("Longitude"); } } private void convertDeviceControllerWebsite(final JsonNode obj) { final ObjectNode node = (ObjectNode) obj.path("DeviceController"); final JsonNode current = node.path("Website"); if (!current.isMissingNode() && !current.isNull()) { node.put("Website", this.createValueDatatype("uri", current.asText())); } if (current.isNull()) { node.remove("Website"); } } private void convertDeviceOwnerWebsite(final JsonNode obj) { final ObjectNode node = (ObjectNode) obj.path("DeviceOwner"); final JsonNode current = node.path("Website"); if (!current.isMissingNode() && !current.isNull()) { node.put("Website", this.createValueDatatype("uri", current.asText())); } if (current.isNull()) { node.remove("Website"); } } private JsonNode createValueDatatype(final String datatype, final String value) { final ObjectNode node = mapper.createObjectNode(); node.put(ExtendedJsonTokenizer.DATATYPE_LABEL, datatype); node.put(ExtendedJsonTokenizer.DATATYPE_VALUES, value); return node; } public void close() throws IOException { generator.close(); } public static void main(final String[] args) throws IOException { final DatatypeConverter preprocessing = new DatatypeConverter(); preprocessing.process(); preprocessing.close(); } }