# Replace Set.removeAll With ForEach
# Description
Calling the method java.util.Set#removeAll(java.util.Collection) (opens new window) with an instance of java.util.List (opens new window) as an argument may lead to performance problems due to a possible O(n^2) complexity. This rule replaces such invocations. For example, the invocation mySet.removeAll(myList); is replaced by myList.forEach(mySet::remove);.
# Benefits
The benefit of applying this rule may depend on your installed Java version and on the subtype of the Set on which the 'removeAll' method is invoked. Benchmark tests on our systems indicated an improvement. However, we recommend you to carry out all necessary performance tests before applying this rule.
# Tags
Tags
# Code Changes
# Remove all elements of an ArrayList from a HashSet
Pre
void removeStringsFromSet(Set<String> stringSet, List<String> stringList) {
stringSet.removeAll(stringList);
}
Post
void removeStringsFromSet(Set<String> stringSet, List<String> stringList) {
stringList.forEach(stringSet::remove);
}
You Want To Have Those Changes Done Automatically?
The automatic application of this rule is supported in the following jSparrow version:
# Properties
| Property | Value |
|---|---|
| Rule ID | ReplaceSetRemoveAllWithForEach |
| First seen in jSparrow version | 4.13.0 |
| Minimum Java version | 8 |
| Remediation cost | 5 min |