Introduction to Ka Commons Collections framework in the Java Class Library
Introduction to Ka Commons Collections framework in the Java Class Library
Ka Commons Collections is an open source Java class library that provides a set of powerful collection classes and data structures, which is more flexible and easy to use than the collection classes in the Java standard library.It can help developers handle the set related operations in Java more efficiently.
Ka Commons Collections provides many commonly used collection interfaces and implementation classes, such as List, SET, MAP, etc.It also provides some additional functions, such as built -in iterators, sorting and filtering functions, and some optimized data structure implementation.
The following is a brief introduction to the characteristics and usage of some Ka Commons Collections:
1. LinkedList: Ka Commons Collections provides a functional linked list, which can efficiently insert, delete and access operations.
LinkedList<String> linkedList = new LinkedList<>();
linkedList.add("Java");
linkedList.add("Python");
linkedList.add("C++");
for (String language : linkedList) {
System.out.println(language);
}
2. TreeSet: Ka Commons Collections provides an orderly SET collection based on red and black trees, which can easily insert, delete and find operations for elements.
TreeSet<Integer> treeSet = new TreeSet<>();
treeSet.add(5);
treeSet.add(3);
treeSet.add(7);
System.out.println (treeset.first ()); // Output: 3
System.out.println (treeset.last ()); // Output: 7
3. Use iterators to traverse: Ka Commons Collections provides a convenient and efficient iterator that can help developers recycling on the collection class.
ArrayList<String> arrayList = new ArrayList<>();
arrayList.add("Apple");
arrayList.add("Banana");
arrayList.add("Orange");
Iterator<String> iterator = arrayList.iterator();
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
4. Filter mode: Ka Commons Collections provides a powerful filter mode that can be filtered by the set condition to retain only qualified elements.
ArrayList<Integer> numbers = new ArrayList<>();
numbers.add(5);
numbers.add(10);
numbers.add(15);
numbers.add(20);
Predicate<Integer> evenPredicate = n -> n % 2 == 0;
CollectionUtils.filter(numbers, evenPredicate);
for (Integer number : numbers) {
System.out.println (number); // Output: 10 20
}
5. Transformer: Ka Commons Collections provides a converter mode that can convert the elements in the set.
ArrayList<String> fruits = new ArrayList<>();
fruits.add("apple");
fruits.add("banana");
fruits.add("orange");
Transformer<String, String> upperCaseTransformer = String::toUpperCase;
CollectionUtils.transform(fruits, upperCaseTransformer);
for (String fruit : fruits) {
System.out.println (fruit); // Output: Apple Banana Orange
}
Summarize:
Ka Commons Collections is a powerful Java collection framework that provides many commonly used collection classes and related functions.Using it can help developers handle and operate collection data in Java more efficiently to improve development efficiency.Whether it is a linked list, a tree -shaped collection, or iterator, filter, and converter mode, Ka Commons Collections provides developers with rich choices and flexibility.
Please note that the code in the above example is only used to demonstrate and explain the usage of Ka Commons Collections framework, which does not represent a complete code implementation.In actual use, appropriate adjustments and expansion are needed according to specific needs.
