rspec/rules/S2230/java/rule.adoc

== Why is this an issue?

Marking a non-public method `@Async` or `@Transactional` is misleading because Spring does not recognize non-public methods, and so makes no provision for their proper invocation.
Nor does Spring make provision for the methods invoked by the method it called.

Therefore marking a private method, for instance, @Transactional can only result in a runtime error or exception if the method is annotated as @Transactional.

== How to fix it

Declare the method `public`.
Note that this action alone does not resolve the issue of direct instance calls from within the same class (see rule S6809), but it is a required precondition to fix it.

=== Code examples

==== Noncompliant code example

[source,java,diff-id=1,diff-type=noncompliant]
----
@Async
private Future<String> asyncMethodWithReturnType() { // Noncompliant, no proxy generated and
    return "Hellow, world!";                         // can only be invoked from same class
}
----

==== Compliant solution

[source,java,diff-id=1,diff-type=compliant]
----
@Async
public Future<String> asyncMethodWithReturnType() { // Compliant
    return "Hellow, world!";
}
----


== Resources

=== Documentation

- https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/scheduling/annotation/Async.html[Spring Framework API - Annotation Interface Async]
- https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/transaction/annotation/Transactional.html[Spring Framework API - Annotation Interface Transactional]

=== Articles & blog posts

- https://www.baeldung.com/spring-async[Baeldung - How To Do @Async in Spring]
- https://stackoverflow.com/questions/22561775/spring-async-ignored[Stack Overflow - Spring @Async ignored]
- https://stackoverflow.com/questions/4396284/does-spring-transactional-attribute-work-on-a-private-method[Stack Overflow - Does Spring @Transactional attribute work on a private method?]


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== Comments And Links
(visible only on this page)

=== on 21 Nov 2014, 12:28:29 Freddy Mallet wrote:
Two questions/remarks:

* Are we talking about private methods or about non-public methods ? If my feeling is correct this rule should only target private methods
* I would tag the rule with the label "spring"
* As this rule is associated to the Reliability characteristic, I think the default severity should be "Critical"

=== on 21 Nov 2014, 13:28:08 Ann Campbell wrote:
The Spring docs are pretty clear that only `public` method can actually be `@Transactional`

=== on 21 Nov 2014, 14:14:44 Freddy Mallet wrote:
Ok Ann, so I would replace :


"Therefore marking a private method"


by


"Therefore marking for instance a private method"


to prevent any misunderstanding

=== on 27 Nov 2018, 13:06:43 Semyon Danilov wrote:
\[~ann.campbell.2] Actually, any method can be Transactional if you're using AspectJ compiler, it's stated in the docs https://docs.spring.io/spring/docs/4.2.x/spring-framework-reference/html/transaction.html[here]. The excerpt:


----
Method visibility and @Transactional

When using proxies, you should apply the @Transactional annotation only to methods with public visibility. If you do annotate protected, private or package-visible methods with the @Transactional annotation, no error is raised, but the annotated method does not exhibit the configured transactional settings. Consider the use of AspectJ (see below) if you need to annotate non-public methods.
----

=== on 27 Nov 2018, 13:33:30 Ann Campbell wrote:
FYI [~alexandre.gigleux] ^

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