Use Java 9-17 APIs and patterns

[marcphilipp]

Overview

• Use enhanced switch expressions
• Use immutable collection factory methods
• Delete CollectionUtils.toSet
• Replace CollectionUtils.toUnmodifiableList() with Stream.toList()
• Pass Charset directly
• Delete PackageNameUtils
• Delete unused methods
• Remove unnecessary non-capturing groups
• Simplify usage of Optional
• Use records
• Use pattern variables
• Deprecate Filter#adaptFilter
• Replace Collectors.toList() with Stream.toList()
• Use more immutable collection factory methods
• Fix nullability annotations in ReflectionUtils and AnnotationSupport
• Fix nullability annotation in RecordArguments
• Remove unnecessary reflection
• Remove unused method

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I hereby agree to the terms of the JUnit Contributor License Agreement.

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests including corner cases, errors, and exception handling
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes

[sormuras]

Great!