org.jsfr.json.GsonParser.java Source code

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Here is the source code for org.jsfr.json.GsonParser.java

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/*
 * MIT License
 *
 * Copyright (c) 2019 WANG Lingsong
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package org.jsfr.json;

import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import org.jsfr.json.provider.JsonProvider;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;

public class GsonParser implements JsonParserAdapter {

    private static class GsonResumableParser implements ResumableParser {
        private JsonReader jsonReader;
        private SurfingContext context;
        private AbstractPrimitiveHolder stringHolder;
        private AbstractPrimitiveHolder numberHolder;
        private AbstractPrimitiveHolder booleanHolder;
        private AbstractPrimitiveHolder nullHolder;

        public GsonResumableParser(JsonReader jsonReader, SurfingContext context,
                AbstractPrimitiveHolder stringHolder, AbstractPrimitiveHolder numberHolder,
                AbstractPrimitiveHolder booleanHolder, AbstractPrimitiveHolder nullHolder) {
            this.jsonReader = jsonReader;
            this.context = context;
            this.stringHolder = stringHolder;
            this.numberHolder = numberHolder;
            this.booleanHolder = booleanHolder;
            this.nullHolder = nullHolder;
        }

        @Override
        public void parse() {
            context.startJSON();
            doParse();
        }

        @Override
        public boolean resume() {
            try {
                if (!context.isPaused()) {
                    return false;
                }
                context.resume();
                doParse();
                return true;
            } catch (Exception e) {
                context.getConfig().getErrorHandlingStrategy().handleParsingException(e);
                return false;
            }
        }

        private void doParse() {
            try {
                while (!context.shouldBreak()) {
                    JsonToken token = jsonReader.peek();
                    switch (token) {
                    case BEGIN_ARRAY:
                        jsonReader.beginArray();
                        context.startArray();
                        break;
                    case END_ARRAY:
                        jsonReader.endArray();
                        context.endArray();
                        break;
                    case BEGIN_OBJECT:
                        jsonReader.beginObject();
                        context.startObject();
                        break;
                    case END_OBJECT:
                        jsonReader.endObject();
                        context.endObject();
                        break;
                    case NAME:
                        String name = jsonReader.nextName();
                        context.startObjectEntry(name);
                        break;
                    case STRING:
                        stringHolder.init();
                        context.primitive(stringHolder);
                        stringHolder.skipValue();
                        break;
                    case NUMBER:
                        numberHolder.init();
                        context.primitive(numberHolder);
                        numberHolder.skipValue();
                        break;
                    case BOOLEAN:
                        booleanHolder.init();
                        context.primitive(booleanHolder);
                        booleanHolder.skipValue();
                        break;
                    case NULL:
                        nullHolder.init();
                        context.primitive(nullHolder);
                        nullHolder.skipValue();
                        break;
                    case END_DOCUMENT:
                        context.endJSON();
                        break;
                    }
                }
            } catch (Exception e) {
                context.getConfig().getErrorHandlingStrategy().handleParsingException(e);
            }
        }
    }

    public final static GsonParser INSTANCE = new GsonParser();

    private JsonReaderFactory jsonReaderFactory;

    public GsonParser() {
        this.jsonReaderFactory = new DefaultJsonReaderFactory();
    }

    public GsonParser(JsonReaderFactory jsonReaderFactory) {
        this.jsonReaderFactory = jsonReaderFactory;
    }

    @Override
    public void parse(Reader reader, SurfingContext context) {
        createResumableParser(reader, context).parse();
    }

    @Override
    public void parse(String json, SurfingContext context) {
        createResumableParser(json, context).parse();
    }

    @Override
    public void parse(InputStream inputStream, SurfingContext context) {
        createResumableParser(inputStream, context).parse();
    }

    @Override
    public ResumableParser createResumableParser(Reader reader, SurfingContext context) {
        return createResumableParserImpl(reader, context);
    }

    private ResumableParser createResumableParserImpl(Reader reader, SurfingContext context) {

        final JsonReader jsonReader = this.jsonReaderFactory.createJsonReader(reader);
        final JsonProvider jsonProvider = context.getConfig().getJsonProvider();

        AbstractPrimitiveHolder stringHolder = new AbstractPrimitiveHolder(context.getConfig()) {
            @Override
            public Object doGetValue() throws IOException {
                return jsonProvider.primitive(jsonReader.nextString());
            }

            @Override
            public void doSkipValue() throws IOException {
                jsonReader.skipValue();
            }
        };
        AbstractPrimitiveHolder numberHolder = new AbstractPrimitiveHolder(context.getConfig()) {
            @Override
            public Object doGetValue() throws IOException {
                return jsonProvider.primitive(jsonReader.nextDouble());
            }

            @Override
            public void doSkipValue() throws IOException {
                jsonReader.skipValue();
            }
        };
        AbstractPrimitiveHolder booleanHolder = new AbstractPrimitiveHolder(context.getConfig()) {
            @Override
            public Object doGetValue() throws IOException {
                return jsonProvider.primitive(jsonReader.nextBoolean());
            }

            @Override
            public void doSkipValue() throws IOException {
                jsonReader.skipValue();
            }
        };
        AbstractPrimitiveHolder nullHolder = new AbstractPrimitiveHolder(context.getConfig()) {
            @Override
            public Object doGetValue() throws IOException {
                jsonReader.nextNull();
                return jsonProvider.primitiveNull();
            }

            @Override
            public void doSkipValue() throws IOException {
                jsonReader.skipValue();
            }
        };
        return new GsonResumableParser(jsonReader, context, stringHolder, numberHolder, booleanHolder, nullHolder);
    }

    @Override
    public ResumableParser createResumableParser(String json, SurfingContext context) {
        return createResumableParser(new StringReader(json), context);
    }

    @Override
    public ResumableParser createResumableParser(InputStream json, SurfingContext context) {
        return createResumableParserImpl(new InputStreamReader(json, context.getConfig().getParserCharset()),
                context);
    }

    @Override
    public NonBlockingParser createNonBlockingParser(SurfingContext context) {
        throw new UnsupportedOperationException("Unsupported");
    }

}