Java中的 AbstractSequentialList 和示例

Java中的AbstractSequentialList类是Java Collection Framework 的一部分，实现了Collection 接口和AbstractCollection 类。它用于实现一个不可修改的列表，只需要扩展这个 AbstractList 类并实现 get() 和 size() 方法。

此类提供 List 接口的骨架实现，以最大限度地减少实现此接口所需的工作，该接口由“顺序访问”数据存储（例如链表）支持。对于随机访问数据（如数组），应优先使用 AbstractList 而非此类。

类层次结构：

宣言：

public abstract class AbstractSequentialList
    extends AbstractList

Where E is the type of element maintained by this List.

它实现了 Iterable 、 Collection 、 List 接口。 LinkedList 是 AbstractSequentialList 的唯一直接子类。

构造函数： protected AbstractSequentialList() –默认构造函数，但受到保护，它不允许创建 AbstractSequentialList 对象。

AbstractSequentialList asl = new LinkedList();  

示例 1： AbstractSequentialList 是一个抽象类，因此应该为其分配一个其子类的实例，例如 LinkedList。

Java

// Java code to illustrate AbstractSequentialList
import java.util.*;
  
public class GfG {
  
    public static void main(String[] args)
    {
        // Creating an instance of
        // the AbstractSequentialList
        AbstractSequentialList absl
            = new LinkedList<>();
  
        // adding elements to absl
        absl.add(5);
        absl.add(6);
        absl.add(7);
  
        // Printing the list
        System.out.println(absl);
    }
}

输出：

[5, 6, 7]

示例 2：

Java

// Java code to illustrate
// methods of AbstractSequentialList
  
import java.util.*;
import java.util.AbstractSequentialList;
  
public class AbstractSequentialListDemo {
    public static void main(String args[])
    {
  
        // Creating an empty AbstractSequentialList
        AbstractSequentialList
            absqlist = new LinkedList();
  
        // Using add() method to
          // add elements in the list
        absqlist.add("Geeks");
        absqlist.add("for");
        absqlist.add("Geeks");
        absqlist.add("10");
        absqlist.add("20");
  
        // Output the list
        System.out.println("AbstractSequentialList: "
                           + absqlist);
  
        // Remove the head using remove()
        absqlist.remove(3);
  
        // Print the final list
        System.out.println("Final List: "
                           + absqlist);
  
        // Fetching the specific 
          // element from the list
        // using get() method
        System.out.println("The element is: "
                           + absqlist.get(2));
    }
}

输出：

AbstractSequentialList: [Geeks, for, Geeks, 10, 20]
Final List: [Geeks, for, Geeks, 20]
The element is: Geeks

AbstractSequentialList 的方法

METHOD	DESCRIPTION
add​(int index, E element)	Inserts the specified element at the specified position in this list (optional operation).
addAll​(int index, Collection c)	Inserts all of the elements in the specified collection into this list at the specified position (optional operation).
get​(int index)	Returns the element at the specified position in this list.
iterator()	Returns an iterator over the elements in this list (in proper sequence).
listIterator​(int index)	Returns a list iterator over the elements in this list (in proper sequence).
remove​(int index)	Removes the element at the specified position in this list (optional operation).
set​(int index, E element)	Replaces the element at the specified position in this list with the specified element (optional operation).

从类Java.util.AbstractList 继承的方法

METHOD	DESCRIPTION
add​(E e)	Appends the specified element to the end of this list (optional operation).
clear()	Removes all of the elements from this list (optional operation).
equals​(Object o)	Compares the specified object with this list for equality.
hashCode()	Returns the hash code value for this list.
indexOf​(Object o)	Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.
lastIndexOf​(Object o)	Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.
listIterator()	Returns a list iterator over the elements in this list (in proper sequence).
removeRange​(int fromIndex, int toIndex)	Removes from this list all of the elements whose index is between fromIndex, inclusive, and toIndex, exclusive.
subList​(int fromIndex, int toIndex)	Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive.

从类Java.util.AbstractCollection 继承的方法

METHOD	DESCRIPTION
addAll​(Collection c)	Adds all of the elements in the specified collection to this collection (optional operation).
contains​(Object o)	Returns true if this collection contains the specified element.
containsAll​(Collection c)	Returns true if this collection contains all of the elements in the specified collection.
isEmpty()	Returns true if this collection contains no elements.
remove​(Object o)	Removes a single instance of the specified element from this collection, if it is present (optional operation).
removeAll​(Collection c)	Removes all of this collection’s elements that are also contained in the specified collection (optional operation).
retainAll​(Collection c)	Retains only the elements in this collection that are contained in the specified collection (optional operation).
toArray()	Returns an array containing all of the elements in this collection.
toArray​(T[] a)	Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.
toString()	Returns a string representation of this collection.

从接口Java.util.Collection 继承的方法

METHOD	DESCRIPTION
parallelStream()	Returns a possibly parallel Stream with this collection as its source.
removeIf​(Predicate filter)	Removes all of the elements of this collection that satisfy the given predicate.
stream()	Returns a sequential Stream with this collection as its source.
toArray​(IntFunction generator)	Returns an array containing all of the elements in this collection, using the provided generator function to allocate the returned array.

从接口Java.lang.Iterable 继承的方法

METHOD	DESCRIPTION
forEach​(Consumer action)	Performs the given action for each element of the Iterable until all elements have been processed or the action throws an exception.

从接口Java .util.List 继承的方法

METHOD	DESCRIPTION
addAll​(Collection c)	Appends all of the elements in the specified collection to the end of this list, in the order that they are  returned by the specified collection’s iterator (optional operation).
contains​(Object o)	Returns true if this list contains the specified element.
containsAll​(Collection c)	Returns true if this list contains all of the elements of the specified collection.
isEmpty()	Returns true if this list contains no elements.
remove​(Object o)	Removes the first occurrence of the specified element from this list, if it is present (optional operation).
removeAll​(Collection c)	Removes from this list all of its elements that are contained in the specified collection (optional operation).
replaceAll​(UnaryOperator operator)	Replaces each element of this list with the result of applying the operator to that element.
retainAll​(Collection c)	Retains only the elements in this list that are contained in the specified collection (optional operation).
size()	Returns the number of elements in this list.
sort​(Comparator c)	Sorts this list according to the order induced by the specified Comparator.
spliterator()	Creates a Spliterator over the elements in this list.
toArray()	Returns an array containing all of the elements in this list in proper sequence (from first to last element).
toArray​(T[] a)	Returns an array containing all of the elements in this list in proper sequence (from first to last element);  the runtime type of the returned array is that of the specified array.

参考： Java : Java