org.dbrain.data.jackson.serializers.JacksonSerializationUtils.java Source code

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Here is the source code for org.dbrain.data.jackson.serializers.JacksonSerializationUtils.java

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/*
 * Copyright [2015] [Eric Poitras]
 *
 *     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.dbrain.data.jackson.serializers;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationContext;
import org.dbrain.data.Value;
import org.dbrain.data.ValueList;
import org.dbrain.data.ValueMap;
import org.dbrain.data.impl.value.NullValueImpl;

import java.io.IOException;

/**
 * Created by epoitras on 08/01/15.
 */
public class JacksonSerializationUtils {

    /**
     * Helper method to ensure to get the current token.
     */
    public static JsonToken getToken(JsonParser parser) throws IOException {
        return parser.hasCurrentToken() ? parser.getCurrentToken() : parser.nextToken();
    }

    public static Value parseValue(JsonParser parser, DeserializationContext ctxt) throws IOException {
        JsonToken token = getToken(parser);
        if (token != null) {
            Value result;
            switch (token) {
            case VALUE_STRING:
                result = Value.of(parser.getValueAsString());
                break;
            case VALUE_NUMBER_FLOAT:
                result = Value.of(parser.getDoubleValue());
                break;
            case VALUE_NUMBER_INT:
                result = Value.of(parser.getBigIntegerValue());
                break;
            case VALUE_NULL:
                result = NullValueImpl.NULL;
                break;
            case VALUE_TRUE:
                result = Value.of(Boolean.TRUE);
                break;
            case VALUE_FALSE:
                result = Value.of(Boolean.FALSE);
                break;
            case START_OBJECT: {
                ValueMap values = ValueMap.newInstance();
                while (parser.nextToken() == JsonToken.FIELD_NAME) {
                    String key = parser.getCurrentName();
                    parser.nextToken();
                    Value v = parseValue(parser, ctxt);
                    if (v == null) {
                        throw ctxt.wrongTokenException(parser, JsonToken.START_OBJECT, "Expected Value");
                    }
                    values.put(key, v);
                }
                if (getToken(parser) == JsonToken.END_OBJECT) {
                    parser.clearCurrentToken();
                } else {
                    throw ctxt.wrongTokenException(parser, JsonToken.END_OBJECT, null);
                }
                result = values;
            }
                break;
            case START_ARRAY: {
                ValueList values = ValueList.newInstance();
                while (parser.nextToken() != JsonToken.END_ARRAY) {
                    Value v = parseValue(parser, ctxt);
                    if (v == null) {
                        throw ctxt.wrongTokenException(parser, JsonToken.START_OBJECT, "Expected Value");
                    }
                    values.add(v);
                }
                if (getToken(parser) == JsonToken.END_ARRAY) {
                    parser.clearCurrentToken();
                } else {
                    throw ctxt.wrongTokenException(parser, JsonToken.END_ARRAY, null);
                }
                result = values;
            }
                break;
            default:
                throw ctxt.wrongTokenException(parser, JsonToken.START_OBJECT, "Expected Value");
            }
            return result;
        } else {
            return null;
        }
    }
}