Package com.puppycrawl.tools.checkstyle.utils

Class UnmodifiableCollectionUtil

  • public final class UnmodifiableCollectionUtil
extends java.lang.Object

    Note: it simply wraps the existing JDK methods to provide a workaround for Pitest survival on mutation for removal of immutable wrapping, see #13127 for more details.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private UnmodifiableCollectionUtil()
      Private constructor for UnmodifiableCollectionUtil.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static <T> T[] copyOfArray​(T[] array, int length)
      Creates a copy of array.
      static <K,​V>
      java.util.Map<K,​V>      		 copyOfMap​(java.util.Map<? extends K,​? extends V> map)
      Creates a copy of Map.
      static <T> java.util.Set<T> singleton​(T obj)
      Returns an immutable set containing only the specified object.
      static <T> java.util.List<T> unmodifiableList​(java.util.List<T> collection)
      Creates an unmodifiable list based on the provided collection.
      static <T> java.util.Set<T> unmodifiableSet​(java.util.Set<T> collection)
      Creates an unmodifiable set based on the provided collection.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • unmodifiableSet

        public static <T> java.util.Set<T> unmodifiableSet​(java.util.Set<T> collection)
        Creates an unmodifiable set based on the provided collection.
        Type Parameters:
        T - the type of elements in the set
        Parameters:
        collection - the collection to create an unmodifiable set from
        Returns:
        an unmodifiable set containing the elements from the provided collection

      • unmodifiableList

        public static <T> java.util.List<T> unmodifiableList​(java.util.List<T> collection)
        Creates an unmodifiable list based on the provided collection.
        Type Parameters:
        T - the type of elements in the set
        Parameters:
        collection - the collection to create an unmodifiable list from
        Returns:
        an unmodifiable list containing the elements from the provided collection

      • copyOfArray

        public static <T> T[] copyOfArray​(T[] array,
                                  int length)
        Creates a copy of array.
        Type Parameters:
        T - The type of array
        Parameters:
        array - Array to create a copy of
        length - length of array
        Returns:
        copy of array

      • copyOfMap

        public static <K,​V> java.util.Map<K,​V> copyOfMap​(java.util.Map<? extends K,​? extends V> map)
        Creates a copy of Map.
        Type Parameters:
        K - the type of keys in the map
        V - the type of values in the map
        Parameters:
        map - map to create a copy of
        Returns:
        an immutable copy of the input map

      • singleton

        public static <T> java.util.Set<T> singleton​(T obj)
        Returns an immutable set containing only the specified object.
        Type Parameters:
        T - the type of object
        Parameters:
        obj - the type of object in the set
        Returns:
        immutable set