GsonJsonHandler.java

package com.meilisearch.sdk.json;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonSyntaxException;
import com.google.gson.reflect.TypeToken;
import com.meilisearch.sdk.exceptions.JsonDecodingException;
import com.meilisearch.sdk.exceptions.JsonEncodingException;
import com.meilisearch.sdk.exceptions.MeilisearchException;
import com.meilisearch.sdk.model.FilterableAttribute;
import com.meilisearch.sdk.model.Key;

public class GsonJsonHandler implements JsonHandler {

    private final Gson gson;

    public GsonJsonHandler() {
        GsonBuilder builder = new GsonBuilder();
        builder.registerTypeAdapter(Key.class, new GsonKeyTypeAdapter());
        builder.registerTypeAdapter(
                FilterableAttribute.class, new GsonFilterableAttributeSerializer());
        this.gson = builder.create();
    }

    @Override
    public String encode(Object o) throws MeilisearchException {
        if (o != null && o.getClass() == String.class) {
            return (String) o;
        }

        try {
            return gson.toJson(o);
        } catch (Exception e) {
            throw new JsonEncodingException(e);
        }
    }

    @Override
    @SuppressWarnings("unchecked")
    public <T> T decode(Object o, Class<T> targetClass, Class<?>... parameters)
            throws MeilisearchException {
        if (o == null) {
            throw new JsonDecodingException("Response to deserialize is null");
        }
        if (targetClass == String.class) {
            return (T) o;
        }
        try {
            if (parameters == null || parameters.length == 0) {
                return gson.fromJson((String) o, targetClass);
            } else {
                TypeToken<?> parameterized = TypeToken.getParameterized(targetClass, parameters);
                return gson.fromJson((String) o, parameterized.getType());
            }
        } catch (JsonSyntaxException e) {
            throw new JsonDecodingException(e);
        }
    }
}