org.kjots.json.content.io.simple.SimpleJsonReader.java Source code

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Here is the source code for org.kjots.json.content.io.simple.SimpleJsonReader.java

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/* 
 * Copyright  2010 Karl J. Ots <kjots@kjots.org>
 * 
 * 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 org.kjots.json.content.io.simple;

import java.io.IOException;
import java.io.Reader;
import java.math.BigDecimal;

import org.kjots.json.content.io.JsonReader;
import org.kjots.json.content.io.JsonReaderException;
import org.kjots.json.content.rebase.org.json.simple.parser.ContentHandler;
import org.kjots.json.content.rebase.org.json.simple.parser.JSONParser;
import org.kjots.json.content.rebase.org.json.simple.parser.ParseException;
import org.kjots.json.content.shared.AbstractJsonContentGenerator;

/**
 * Simple JSON Reader.
 * <p>
 * This class implements a JSON reader backed the parser from JSON.simple
 * [<a href="http://code.google.com/p/json-simple/">http://code.google.com/p/json-simple/</a>],
 * slightly modified to remove functionality not relevant to this library.
 * <p>
 * Created: 1st February 2010.
 *
 * @author <a href="mailto:kjots@kjots.org">Karl J. Ots &lt;kjots@kjots.org&gt;</a>
 * @since 1.0
 */
public class SimpleJsonReader extends AbstractJsonContentGenerator implements JsonReader {
    /**
     * Parse the given JSON text.
     * 
     * @param jsonText The JSON text.
     * @throws JsonReaderException
     */
    @Override
    public void parse(String jsonText) throws JsonReaderException {
        try {
            new JSONParser().parse(jsonText, this.createContentHandler());
        } catch (ParseException pe) {
            throw new JsonReaderException(pe);
        }
    }

    /**
     * Parse the JSON text provided by the given reader.
     * 
     * @param reader The reader.
     * @throws IOException
     * @throws JsonReaderException
     */
    @Override
    public void parse(Reader reader) throws IOException, JsonReaderException {
        try {
            new JSONParser().parse(reader, this.createContentHandler());
        } catch (ParseException pe) {
            throw new JsonReaderException(pe);
        }
    }

    /**
     * Create the content handler.
     *
     * @return The content handler.
     */
    private ContentHandler createContentHandler() {
        return new ContentHandler() {
            @Override
            public void startJSON() {
                SimpleJsonReader.this.jsonContentHandler.startJson();
            }

            @Override
            public void endJSON() {
                SimpleJsonReader.this.jsonContentHandler.endJson();
            }

            @Override
            public boolean startObject() {
                SimpleJsonReader.this.jsonContentHandler.startObject();

                return true;
            }

            @Override
            public boolean endObject() {
                SimpleJsonReader.this.jsonContentHandler.endObject();

                return true;
            }

            @Override
            public boolean startObjectEntry(String key) {
                SimpleJsonReader.this.jsonContentHandler.memberName(key);

                return true;
            }

            @Override
            public boolean endObjectEntry() {
                return true;
            }

            @Override
            public boolean startArray() {
                SimpleJsonReader.this.jsonContentHandler.startArray();

                return true;
            }

            @Override
            public boolean endArray() {
                SimpleJsonReader.this.jsonContentHandler.endArray();

                return true;
            }

            @Override
            public boolean primitive(Object value) {
                if (value instanceof BigDecimal) {
                    BigDecimal numericValue = (BigDecimal) value;

                    // Attempt to coerce the value into an integer
                    try {
                        value = Integer.valueOf(numericValue.intValueExact());
                    } catch (ArithmeticException ae1) {
                        // Attempt to coerce the value into a long
                        try {
                            value = Long.valueOf(numericValue.longValueExact());
                        } catch (ArithmeticException ae2) {
                            // Attempt to coerce the value into a BigInteger
                            try {
                                value = numericValue.toBigIntegerExact();
                            } catch (ArithmeticException ae3) {
                                // Ignore this exception - value will remain a BigDecimal
                            }
                        }
                    }
                }

                SimpleJsonReader.this.jsonContentHandler.primitive(value);

                return true;
            }
        };
    }
}