Loop can be collapsed with Stream API

Reports loops which can be replaced with stream API calls using lambda expressions.

Such a replacement changes the style from imperative to more functional and makes the code more compact.

Example:

boolean check(List<String> data) {
  for (String e : data) {
    String trimmed = e.trim();
    if (!trimmed.startsWith("xyz")) {
      return false;
    }
  }
  return true;
}

After the quick-fix is applied:

boolean check(List<String> data) {
  return data.stream().map(String::trim).allMatch(trimmed -> trimmed.startsWith("xyz"));
}

This inspection only reports if the language level of the project or module is 8 or higher.

Inspection options

Option	Type	Default
Warn if only 'forEach' replacement is available	Checkbox	false
Warn if the loop is trivial	Checkbox	false

Inspection Details
Available in:	IntelliJ IDEA 2023.3, Qodana for JVM 2023.3
Plugin:	Java, 233.SNAPSHOT

Last modified: 13 July 2023