我们可以使用“Optional”在 Groovy 中进行空值检查吗

Question

I have very little knowledge on Groovy. I am using Groovy 2.4.12 .

I would like to do null check on a variable which can be primitive or object. So I am trying to use Optional utility to do null check. I am getting Optional can not be resolved .

if(Optional.ofNullable(${value}).orElse(null) != null) {};

${value} will be mapped from java code.

Answer 1

Optional was introduced in Java 1.8 ( https://docs.oracle.com/javase/8/docs/api/java/util/Optional.html )

Groovy 2.4.12 uses Java 1.7 (here's the matric http://groovy-lang.org/download.html#requirements )

If you have Java 1.8+ installed, Groovy should be able to use Optional , provided it java.util.* or java.util.Optional was imported.

With the code sample you provided it is unclear what you're actually trying to accomplish, but, strictly speaking, Optional does not save you from checking for null , you just do it differently.