cf.adriantodt.utils.data.ConfigUtils.java Source code

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Here is the source code for cf.adriantodt.utils.data.ConfigUtils.java

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/*
 * This class was created by <AdrianTodt>. It's distributed as
 * part of the DavidBot. Get the Source Code in github:
 * https://github.com/adriantodt/David
 *
 * DavidBot is Open Source and distributed under the
 * GNU Lesser General Public License v2.1:
 * https://github.com/adriantodt/David/blob/master/LICENSE
 *
 * File Created @ [05/11/16 22:09]
 */

package cf.adriantodt.utils.data;

import com.google.gson.*;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Map;
import java.util.Optional;
import java.util.function.Predicate;
import java.util.function.Supplier;

import static cf.adriantodt.utils.data.DBUtils.getPath;

public class ConfigUtils {
    private static final Charset UTF8 = Charset.forName("UTF-8");
    private static final Logger LOGGER = LogManager.getLogger("ConfigUtils");
    private static final Gson GSON = new GsonBuilder().setPrettyPrinting().serializeNulls().create();

    static {
        File file = new File("./configs/");
        if (!file.isDirectory()) //noinspection ResultOfMethodCallIgnored
            file.delete();
        if (!file.exists()) //noinspection ResultOfMethodCallIgnored
            file.mkdir();
    }

    public static JsonObject get(String name, Map<String, Predicate<JsonElement>> validator,
            Supplier<JsonObject> defaultGenerator, boolean returnGenerated, boolean generateFileOnError) {
        Path path = path(name);
        try {
            JsonElement input = new JsonParser().parse(new String(Files.readAllBytes(path), UTF8));
            JsonObject object = requireObject(input);
            validator.forEach((s, predicate) -> requireValid(object, s, predicate));
            return object;
        } catch (IOException | NullPointerException | IllegalStateException e) {
            LOGGER.error("Error while loading Config file: ", e);
            Optional<Supplier<JsonObject>> optionalGenerator = Optional.ofNullable(defaultGenerator);
            LOGGER.error("Configuration File not found or damaged." + (optionalGenerator.isPresent()
                    ? (generateFileOnError ? " Generating one at " + path + "..." : "")
                            + (returnGenerated ? " The Generated Default Object will be returned." : "")
                    : " No Generator found."));
            if (!optionalGenerator.isPresent()) {
                return null;
            } else {
                JsonObject defaultObj = optionalGenerator.get().get();

                if (generateFileOnError) {
                    try {
                        Files.write(path, GSON.toJson(defaultObj).getBytes(Charset.forName("UTF-8")));
                        LOGGER.error("Configuration File generated.");
                    } catch (Exception ex) {
                        LOGGER.error("Configuration File could not be generated. Please fix the permissions.");
                    }
                }

                if (returnGenerated)
                    return defaultObj;
            }
        }

        return null;
    }

    private static Path path(String name) {
        return getPath("configs/" + name, "json");
    }

    public static boolean isJsonString(JsonElement element) {
        return element.isJsonPrimitive() && element.getAsJsonPrimitive().isString();
    }

    public static boolean isJsonNumber(JsonElement element) {
        return element.isJsonPrimitive() && element.getAsJsonPrimitive().isNumber();
    }

    public static void requireValid(JsonObject object, String element, Predicate<JsonElement> correctState) {
        if (!correctState.test(object.get(element)))
            throw new IllegalStateException("\"" + element + "\" is invalid");
    }

    public static JsonObject requireObject(JsonElement element) {
        if (element == null || !element.isJsonObject())
            throw new NullPointerException("the provided " + JsonElement.class + " is not an " + JsonObject.class);

        return element.getAsJsonObject();
    }
}