Objects.deepEquals 方法的含义

Question

问题是关于静态方法的 Objects.deepEquals class（因为 Java 7）：

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);
}

如本方法javadoc中所述：

Returns true if the arguments are deeply equal to each other and false otherwise.

我不明白的是：比较的depth在哪里？正如我们在它的实现中看到的那样，它只是进行引用比较，在 Arrays.deepEquals0(a, b) 内部它调用简单的 Object 和 Object 参数只是：eq = e1.equals(e2);。那么在何种意义上两个对象深度相等？

Answer 1

如果传递 Array 对象，比较将是 deep。

Non-array 对象的评估不会比使用 equals 得到的更深入。

因此深度与您的情况无关：

Two null values are deeply equal. If both arguments are arrays, the algorithm in Arrays.deepEquals is used to determine equality. Otherwise, equality is determined by using the equals method of the first argument.

引自：

Object.deepEquals

Answer 2

您可以参考：Your's Deeply - Why Arrays.deepEquals When We Have Arrays.equals

Arrays.deepEquals looks really deep

From the source, we could understand that Arrays.deepEquals

Loops through the input arrays, gets each pair

Analyses the type of each pair

Delegates the equal deciding logic to one of the overloaded Arrays.equals if they are one of the primitive arrays

Delegates recursively to Arrays.deepEquals if it is an Object array

Calls the respective object’s equals, for any other object

Objects.deepEquals 方法的含义

Meaning of Objects.deepEquals method

java

equals

equality