001/*
002 *  Units of Measurement Jackson Library for JSON support
003 *  Copyright (c) 2012-2019, Werner Keil and others
004 *
005 * All rights reserved.
006 *
007 * Redistribution and use in source and binary forms, with or without modification,
008 * are permitted provided that the following conditions are met:
009 *
010 * 1. Redistributions of source code must retain the above copyright notice,
011 *    this list of conditions and the following disclaimer.
012 *
013 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
014 *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
015 *
016 * 3. Neither the name of JSR-385, Units of Measurement nor the names of their contributors may be used to endorse or promote products
017 *    derived from this software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
021 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
023 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
026 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
028 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package tech.uom.lib.jackson;
031
032import java.io.IOException;
033import java.text.ParsePosition;
034import com.fasterxml.jackson.core.JsonGenerator;
035import com.fasterxml.jackson.core.JsonParser;
036import com.fasterxml.jackson.core.JsonToken;
037import com.fasterxml.jackson.core.Version;
038import com.fasterxml.jackson.databind.DeserializationContext;
039import com.fasterxml.jackson.databind.SerializerProvider;
040import com.fasterxml.jackson.databind.deser.std.StdScalarDeserializer;
041import com.fasterxml.jackson.databind.module.SimpleModule;
042import com.fasterxml.jackson.databind.ser.std.StdScalarSerializer;
043import javax.measure.Dimension;
044import javax.measure.Unit;
045import systems.uom.ucum.format.UCUMFormat;
046import systems.uom.ucum.format.UCUMFormat.Variant;
047
048/**
049 * Configures Jackson to (de)serialize JSR 363 Unit objects using their UCUM representation, since the actual objects don't
050 * translate well into JSON.
051 * @version 2.0
052 */
053public class UnitJacksonModule extends SimpleModule {
054    /**
055     *
056     */
057    private static final long serialVersionUID = 7601584599518016604L;
058
059    public UnitJacksonModule() {
060        super("UnitJsonSerializationModule", new Version(1, 3, 3, null, 
061                UnitJacksonModule.class.getPackage().getName(), "uom-lib-jackson"));
062
063        addSerializer(Unit.class, new UnitJsonSerializer());
064        addSerializer(Dimension.class, new DimensionJsonSerializer());
065        addDeserializer(Unit.class, new UnitJsonDeserializer());
066        addDeserializer(Dimension.class, new DimensionJsonDeserializer());
067    }
068
069    @SuppressWarnings("rawtypes")
070    private class UnitJsonSerializer extends StdScalarSerializer<Unit> {
071        /**
072         *
073         */
074        private static final long serialVersionUID = 2500234678114311932L;
075
076        protected UnitJsonSerializer() {
077            super(Unit.class);
078        }
079
080        @Override
081        public void serialize(Unit unit, JsonGenerator jgen, SerializerProvider provider) throws IOException {
082            if (unit == null) {
083                jgen.writeNull();
084            }
085            else {
086                // Format the unit using the UCUM representation.
087                // The string produced for a given unit is always the same; it is not affected by the locale.
088                // It can be used as a canonical string representation for exchanging units.
089                String ucumFormattedUnit = UCUMFormat.getInstance(Variant.CASE_SENSITIVE).format(unit, new StringBuilder()).toString();
090
091                jgen.writeString(ucumFormattedUnit);
092            }
093        }
094    }
095
096    @SuppressWarnings("rawtypes")
097    private class UnitJsonDeserializer extends StdScalarDeserializer<Unit> {
098        /**
099         *
100         */
101        private static final long serialVersionUID = -6327531740958676293L;
102
103        protected UnitJsonDeserializer() {
104            super(Unit.class);
105        }
106
107        @Override
108        public Unit deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
109            JsonToken currentToken = jsonParser.getCurrentToken();
110
111            if (currentToken == JsonToken.VALUE_STRING) {
112                return UCUMFormat.getInstance(Variant.CASE_SENSITIVE).parse(jsonParser.getText(), new ParsePosition(0));
113            }
114            throw deserializationContext.wrongTokenException(jsonParser, String.class,
115                    JsonToken.VALUE_STRING,
116                    "Expected unit value in String format");
117        }
118    }
119}