ObjectUtils.java

package com.dianping.pigeon.util;

import java.util.Arrays;
import java.util.Comparator;

/**
 * @author qi.yin
 *         2016/05/23  下午4:41.
 */
public class ObjectUtils {

    public static boolean equals(Object a, Object b) {
        return (a == b) || (a != null && a.equals(b));
    }

    public static int hashCode(Object o) {
        return o != null ? o.hashCode() : 0;
    }


    public static int hash(Object... values) {
        return Arrays.hashCode(values);
    }

    public static String toString(Object o) {
        return String.valueOf(o);
    }

    public static String toString(Object o, String nullDefault) {
        return (o != null) ? o.toString() : nullDefault;
    }

    public static <T> int compare(T a, T b, Comparator<? super T> c) {
        return (a == b) ? 0 :  c.compare(a, b);
    }

    public static <T> T requireNonNull(T obj) {
        if (obj == null)
            throw new NullPointerException();
        return obj;
    }

    public static <T> T requireNonNull(T obj, String message) {
        if (obj == null)
            throw new NullPointerException(message);
        return obj;
    }
}