Unused publisher
Reports unused Publisher instances.
To use an operator (a method of Mono/Flux/Flowable object that returns a Mono/Flux/Flowable) that produces a new Publisher instance, you must subscribe to the created Publisher via subscribe().
Using a factory (for example, Mono.just()) without subscribing to the returned Publisher, creates an object that is never used and is treated as unnecessary memory allocation.
For example, Mono.just(1, 2, 3).map(i -> i + 3) won't be executed unless you subscribe to this Publisher, or unless you produce a new Publisher by applying operators and subscribe to it.
Example:
Unused Flux instance:
A Flux instance used by consumer:
Calls to methods annotated with Error Prone's or AssertJ's @CanIgnoreReturnValue annotation are not reported.
Locating this inspection
- By ID
Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.
ReactiveStreamsUnusedPublisher- Via Settings dialog
Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.
New in 2019.3
Suppressing Inspection
You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:
More detailed instructions as well as other ways and options that you have can be found in the product documentation:
Inspection Details | |
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By default bundled with: |