[WEB][42108]Optimized use of Java Optional Else

[JulienBertrand]

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Optimized use of Java Optional Else

Platform

OS	OS Version	Language
		Java

Main characteristics

ID	Title	Category	Sub-category
CRJVM001	Optimized use of Java Optional Else

Severity / Remediation Cost

Severity	Remediation Cost
Minor	Minor

Rule short description

The Optional orElse method always evaluate the "other" argument, whereas the orElseGet only call the given Supplier method passed as an argument when the Optional value isn't present. Evaluate orElse can be inefficient.

Rule short description

Text

Remember (from the Javadoc) that the Supplier method passed as an argument is only executed when an Optional value isn't present.
To avoid unneeded argument evaluation, check that "other" argument of orElse method is never a method call, but simply an object or a static value.

HTML

// Uncompliant code:

String name = Optional.of("ecoCode")
  .orElse(getUnpredictedMethod());

// Compliant code:

String name = Optional.of("ecoCode")
  .orElseGet(() -> getUnpredictedMethod());

Implementation principle

• Search orElse method
• Check if orElse method argument is a call of method
• If true report the Line as uncompliant

References

https://www.baeldung.com/java-optional-or-else-vs-or-else-get

[jhertout]

Reading the link in the description (https://www.baeldung.com/java-optional-or-else-vs-or-else-get) I think we can implement this rule. There is a beginning of measure in the document that is relevant with the rule.

I think the description wording of the rule should be reworked and may be we can perform more measure but the rule seems good to me. May be a good exemple to perform energy measures.

[dedece35]

Hi @jhertout @glalloue
second review OK for this issue.
first ecocode PR (rule specification) merged and updated with real rule ID - see green-code-initiative/creedengo-rules-specifications#323

the 2 nexts PRs will be merged soon once a release of specifications will be done and referenced on ecoCode-java plugin.

What is the process for actual kind of issue ? do we simply close it ?