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ObServe Toolkit Common Dto module

There is a newer version: 4.34

package fr.ird.observe.gson;

/*
 * #%L
 * ObServe Toolkit :: Common Dto
 * %%
 * Copyright (C) 2017 - 2020 IRD, Ultreia.io
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program.  If not, see
 * .
 * #L%
 */

import com.google.common.collect.ImmutableMap;
import com.google.common.reflect.TypeParameter;
import com.google.common.reflect.TypeToken;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Map;

/**
 * @author Tony Chemit - [email protected]
 */
public class ImmutableMapAdapter implements JsonDeserializer> {

    static  TypeToken> mapOf(TypeToken keyType, TypeToken valueType) {
        return new TypeToken>() {
        }
                .where(new TypeParameter() {
                }, keyType)
                .where(new TypeParameter() {
                }, valueType);
    }

    @Override
    public ImmutableMap deserialize(JsonElement json, Type type, JsonDeserializationContext context) throws JsonParseException {

        Type[] actualTypeArguments = ((ParameterizedType) type).getActualTypeArguments();
        Type keyType = actualTypeArguments[0];
        Type valueType = actualTypeArguments[1];

        Type type2 = mapOf(TypeToken.of(keyType), TypeToken.of(valueType)).getType();
        Map map = context.deserialize(json, type2);

        return ImmutableMap.copyOf(map);
    }

}