br.com.objectos.lang.MoreObjects Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of objectos-lang Show documentation
A set of utilities for classes of the java.lang and the java.util packages.
The newest version!
/*
 * Copyright (C) 2011-2021 Objectos Software LTDA.
 *
 * This file is part of the ObjectosComuns project.
 *
 * ObjectosComuns is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * ObjectosComuns 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with ObjectosComuns.  If not, see .
 */
package br.com.objectos.lang;

import static br.com.objectos.lang.Lang.checkNotNull;

final class MoreObjects {

  static final int HASH_CODE_MULTIPLIER = 31;

  static final int HASH_CODE_START = 17;

  private MoreObjects() {}

  public static boolean equals(Object first, Object second) {
    if (first == second) {
      return true;
    }

    if (first != null) {
      return first.equals(second);
    }

    return false;
  }

  public static int hashCode(int hc1, int hc2) {
    int result = HASH_CODE_START;

    result = hashCode0(result, hc1);
    result = hashCode0(result, hc2);

    return result;
  }

  public static int hashCode(int hc1, int hc2, int hc3) {
    int result = HASH_CODE_START;

    result = hashCode0(result, hc1);
    result = hashCode0(result, hc2);
    result = hashCode0(result, hc3);

    return result;
  }

  public static int hashCode(int hc1, int hc2, int hc3, int hc4) {
    int result = HASH_CODE_START;

    result = hashCode0(result, hc1);
    result = hashCode0(result, hc2);
    result = hashCode0(result, hc3);
    result = hashCode0(result, hc4);

    return result;
  }

  public static int hashCode(int hc1, int hc2, int hc3, int hc4, int hc5) {
    int result = HASH_CODE_START;

    result = hashCode0(result, hc1);
    result = hashCode0(result, hc2);
    result = hashCode0(result, hc3);
    result = hashCode0(result, hc4);
    result = hashCode0(result, hc5);

    return result;
  }

  public static int hashCode(int hc1, int hc2, int hc3, int hc4, int hc5, int... rest) {
    checkNotNull(rest, "rest == null");

    int result = HASH_CODE_START;

    result = hashCode0(result, hc1);
    result = hashCode0(result, hc2);
    result = hashCode0(result, hc3);
    result = hashCode0(result, hc4);
    result = hashCode0(result, hc5);

    for (int hc : rest) {
      result = hashCode0(result, hc);
    }

    return result;
  }

  public static int hashCode(Object o) {
    if (o == null) {
      return 0;
    }

    return o.hashCode();
  }

  public static int hashCode(Object o1, Object o2) {
    return hashCode(
        hashCode(o1),
        hashCode(o2)
    );
  }

  public static int hashCode(Object o1, Object o2, Object o3) {
    return hashCode(
        hashCode(o1),
        hashCode(o2),
        hashCode(o3)
    );
  }

  public static int hashCode(Object o1, Object o2, Object o3, Object o4) {
    return hashCode(
        hashCode(o1),
        hashCode(o2),
        hashCode(o3),
        hashCode(o4)
    );
  }

  public static int hashCode(Object o1, Object o2, Object o3, Object o4, Object o5) {
    return hashCode(
        hashCode(o1),
        hashCode(o2),
        hashCode(o3),
        hashCode(o4),
        hashCode(o5)
    );
  }

  public static int hashCode(
      Object o1, Object o2, Object o3, Object o4, Object o5, Object... rest) {
    checkNotNull(rest, "rest == null");

    int result = HASH_CODE_START;

    result = hashCode0(result, hashCode(o1));
    result = hashCode0(result, hashCode(o2));
    result = hashCode0(result, hashCode(o3));
    result = hashCode0(result, hashCode(o4));
    result = hashCode0(result, hashCode(o5));

    for (Object o : rest) {
      result = hashCode0(result, hashCode(o));
    }

    return result;
  }

  static int hashCode0(int current, int hashCode) {
    return HASH_CODE_MULTIPLIER * current + hashCode;
  }

  static int hashCode0(int partial, Object o) {
    return hashCode0(partial, hashCode(o));
  }

}