JAVA之Objects類

　　有了Objects類我們可以簡化一些代碼上的邏輯,我們一起看一下Objects有哪些常用的方法：

public static boolean equals(Object a, Object b) {　　// 比較兩個對象是否相等
        return (a == b) || (a != null && a.equals(b));
}

public static boolean deepEquals(Object a, Object b) { 
        if (a == b)
            return true;
        else if (a == null || b == null)
            return false;
        else
            return Arrays.deepEquals0(a, b);
}
public static <T> int compare(T a, T b, Comparator<? super T> c) {//自定義比較器
        return (a == b) ? 0 :  c.compare(a, b);
}

public static <T> T requireNonNull(T obj) {//不接受為NULL值
        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;
}

public static boolean isNull(Object obj) {//判空
        return obj == null;
}

public static boolean nonNull(Object obj) {//不為空
        return obj != null;
}

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