javaslang.jackson.datatype.deserialize.OptionDeserializer.java Source code

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Here is the source code for javaslang.jackson.datatype.deserialize.OptionDeserializer.java

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/**
 * Copyright 2015 The Javaslang Authors
 *
 * 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 javaslang.jackson.datatype.deserialize;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonMappingException;
import javaslang.control.Option;

import java.io.IOException;

class OptionDeserializer extends ValueDeserializer<Option<?>> {

    private static final long serialVersionUID = 1L;

    private final JavaType javaType;
    private final boolean plainMode;
    private JsonDeserializer<?> stringDeserializer;

    OptionDeserializer(JavaType valueType, boolean plainMode) {
        super(valueType, 1);
        this.javaType = valueType;
        this.plainMode = plainMode;
    }

    @Override
    public Option<?> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
        if (plainMode) {
            Object obj = deserializer(0).deserialize(p, ctxt);
            return Option.of(obj);
        }
        boolean defined = false;
        Object value = null;
        int cnt = 0;
        while (p.nextToken() != JsonToken.END_ARRAY) {
            cnt++;
            switch (cnt) {
            case 1:
                String def = (String) stringDeserializer.deserialize(p, ctxt);
                if ("defined".equals(def)) {
                    defined = true;
                } else if ("undefined".equals(def)) {
                    defined = false;
                } else {
                    throw ctxt.mappingException(javaType.getRawClass());
                }
                break;
            case 2:
                value = deserializer(0).deserialize(p, ctxt);
                break;
            }
        }
        if (defined) {
            if (cnt != 2) {
                throw ctxt.mappingException(javaType.getRawClass());
            }
            return Option.some(value);
        } else {
            if (cnt != 1) {
                throw ctxt.mappingException(javaType.getRawClass());
            }
            return Option.none();
        }
    }

    @Override
    public void resolve(DeserializationContext ctxt) throws JsonMappingException {
        super.resolve(ctxt);
        stringDeserializer = ctxt.findContextualValueDeserializer(ctxt.constructType(String.class), null);
    }

    @Override
    public Option<?> getNullValue(DeserializationContext ctxt) throws JsonMappingException {
        return Option.none();
    }
}