java Objects.isNull(...) / Objects.nonNull(...) 的用途

Purpose of Objects.isNull(...) / Objects.nonNull(...)

提问by Ivan Babanin

What is the purpose of

目的是什么

Objects.isNull(x) 

if we can simply write

如果我们可以简单地写

x == null

?

?

Same for

同为

Objects.nonNull(...)

and

和

x != null

回答by Petr Jane?ek

From the JavaDoc of the method:

从方法的 JavaDoc：

API Note: This method exists to be used as a Predicate, filter(Objects::isNull)

API 注意：此方法存在用作Predicate,filter(Objects::isNull)

回答by rai.skumar

Apart from its obvious usage in the functional world. It can also be used in your normal code in place of ==.

除了它在功能世界中的明显用法。它也可以在您的普通代码中代替==.

Many programmers (including me) think that ( x == nullor x != null) are not object-orientedand hence it makes sense to use object-oriented version.

许多程序员（包括我）认为(x == null或x != null) 不是面向对象的，因此使用面向对象的版本是有意义的。

Objects Java doc:

对象 Java 文档：

This class consists of static utility methods for operating on objects. These utilities include null-safe or null-tolerant methods for computing the hash code of an object, returning a string for an object, and comparing two objects.

此类包含用于操作对象的静态实用程序方法。这些实用程序包括用于计算对象的哈希码、返回对象的字符串以及比较两个对象的空安全或空值容忍方法。

I personally prefer the method version and have been using it for the last couple of years :)

我个人更喜欢方法版本，并且过去几年一直在使用它:)