ph.com.nightowlstudios.utils.Utils Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of edge Show documentation
A simple library for building REST API using Vertx.
There is a newer version: 6.21.1
package ph.com.nightowlstudios.utils;

import io.vavr.control.Try;
import io.vertx.core.json.Json;
import io.vertx.core.json.JsonObject;
import org.apache.commons.lang3.StringUtils;
import ph.com.nightowlstudios.entity.Entity;

import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;
import java.util.function.Supplier;
import java.util.stream.Collectors;

/**
 * @author Joseph Harvey Angeles - @yev
 * @since 9/12/20
 */
public final class Utils {

  private static final String UNDERSCORE = "_";

  private Utils() {
  }

  public static  Optional getFirstElement(List list) {
    return list.isEmpty()
      ? Optional.empty()
      : Optional.ofNullable(list.get(0));
  }

  /**
   * Merges the field values of to onto from, replacing from's value
   * with to's non-null value. If to's value for a certain field
   * is null, resulting return object will take from's value for that field.
   * 


   * This does not mutate the original objects.
   *
   * @param from object to replace values with
   * @param to   object whose values will be used to replace from's
   * @param   Entity.class object should conform to Table.class and
   *             Column.class
   * @return the resulting Entity object.
   * @see ph.com.nightowlstudios.entity.Entity
   * @see ph.com.nightowlstudios.entity.Table
   * @see ph.com.nightowlstudios.entity.Column
   */
  public static  T merge(T from, T to) {
    T result = Json.decodeValue(new JsonObject().encode(), (Class) from.getClass());
    for (Field field : result.getClass().getDeclaredFields()) {
      final String prefix = field.getType().equals(boolean.class) ? "is" : "get";
      Supplier toValue = () -> Try.of(() -> to.getClass()
        .getDeclaredMethod(prefix + StringUtils.capitalize(field.getName()))
        .invoke(to))
        .getOrNull();

      Supplier fromValue = () -> Try.of(() -> from.getClass()
        .getDeclaredMethod(prefix + StringUtils.capitalize(field.getName()))
        .invoke(from))
        .getOrNull();

      if (toValue.get() == null) {
        Try.of(() -> result.getClass()
          .getDeclaredMethod("set" + StringUtils.capitalize(field.getName()), field.getType())
          .invoke(result, fromValue.get()));
      } else {
        Try.of(() -> result.getClass()
          .getDeclaredMethod("set" + StringUtils.capitalize(field.getName()), field.getType())
          .invoke(result, toValue.get()));
      }
    }
    return result;
  }

  public static JsonObject camelCaseKeys(JsonObject json) {
    json.stream()
      .parallel()
      .filter(e -> e.getKey().contains("_"))
      .forEach(e -> {
        json.put(Utils.toCamelCase(e.getKey()), e.getValue());
        json.remove(e.getKey());
      });
    return json;
  }

  public static String toCamelCase(String word) {
    return toCamelCase(word, UNDERSCORE);
  }

  public static String toCamelCase(String word, String separator) {
    if (StringUtils.isBlank(word)) {
      return StringUtils.EMPTY;
    }
    String[] tokens = word.split(separator);
    if (tokens.length == 1) {
      return tokens[0].trim().toLowerCase();
    }
    String head = tokens[0];
    String[] tail = Arrays.copyOfRange(tokens, 1, tokens.length);
    return head.toLowerCase() + Arrays
      .stream(tail)
      .sequential()
      .map(StringUtils::capitalize)
      .collect(Collectors.joining());
  }
}