ModernGsonFileHandler.java

package net.theevilreaper.aves.file;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import net.minestom.server.utils.validate.Check;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Optional;

/**
 * The class represents the implementation of the {@link ModernFileHandler} for the {@link com.google.gson.Gson} library.
 * @author TheMeinerLP
 * @version 1.0.0
 * @since 1.9.0
 */
public class ModernGsonFileHandler implements ModernFileHandler {

    private final Gson gson;

    /**
     * Creates a new instance from the file handler.
     */
    public ModernGsonFileHandler() {
        this.gson = new Gson();
    }

    /**
     * Creates a new instance from the file handler.
     * @param gson the gson instance to deserialize or serialize data
     */
    public ModernGsonFileHandler(Gson gson) {
        this.gson = gson;
    }

    /**
     * Saves a given object into a file.
     * @param path The path where the file is located
     * @param object The object to save
     * @param <T> A generic type for the object value
     */
    @Override
    public <T> void save(Path path, T object, TypeToken<T> typeToken) {
        Check.argCondition(Files.isDirectory(path), "Unable to save a directory. Please check the used path");
        try (var outputStream = Files.newBufferedWriter(path, UTF_8)) {
            if (!Files.exists(path)) {
                var file = Files.createFile(path).getFileName();
                LOGGER.info("Created new file: {}", file);
            }
            gson.toJson(object, typeToken.getRawType(), outputStream);
        } catch (IOException exception) {
            LOGGER.warn("Unable to save file", exception);
        }
    }

    /**
     * Load a given file and parse to the give class.
     * @param path is the where the file is located
     * @param typeToken the type token to deserialize the object
     * @param <T> is generic type for the object value
     * @return a {@link Optional} with the object instance
     */
    @Override
    public <T> Optional<T> load(Path path, TypeToken<T> typeToken) {
        Check.argCondition(Files.isDirectory(path), "Unable to load a directory. Please check the used path");
        if (!Files.exists(path)) {
            return Optional.empty();
        }

        try (var reader = Files.newBufferedReader(path, UTF_8)) {
            return Optional.ofNullable(gson.fromJson(reader, typeToken));
        } catch (IOException exception) {
            LOGGER.warn("Unable to load file", exception);
        }
        return Optional.empty();
    }
}