Redundant 'Collection.addAll()' call

Reports Collection.addAll() and Map.putAll() calls immediately after an instantiation of a collection using a no-arg constructor.

Such constructs can be replaced with a single call to a parametrized constructor, which simplifies the code. Also, for some collections the replacement might be more performant.

Example:

  Set<String> set = new HashSet<>();
  set.addAll(Arrays.asList("alpha", "beta", "gamma"));

After the quick-fix is applied:

Set<String> set = new HashSet<>(Arrays.asList("alpha", "beta", "gamma"));

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.

CollectionAddAllCanBeReplacedWithConstructor

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.

Settings or Preferences | Editor | Inspections | Java | Performance

The JDK collection classes are supported by default. Additionally, you can specify other classes using the Classes to check panel.

Inspection options

Here you can find the description of settings available for the Redundant 'Collection.addAll()' call inspection, and the reference of their default values.

Classes to check: Default value:
Empty

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:

//noinspection CollectionAddAllCanBeReplacedWithConstructor

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025