关于实现链表的底层原理
链表便于增删，不便于查询
package com.littlepage.linkedList;
/**
* 基于底层实现LinkedList
* @author Littlepage
* @reference bjsxt.com
*
*/
public class LittlePagesLinkedList<E> {
private Node first;
private Node last; private int size; public void add(E obj) {
Node node = new Node(obj);
if (first == null) {
node.setPrevious(null);
node.setNext(null);
first = node;
last = node;
} else {
last.setNext(node);
node.setPrevious(last);
node.setNext(null);
last = node;
}
size++;
} public Node getFirst() {
return first;
} public void setFirst(Node first) {
this.first = first;
} public Node getLast() {
return last;
} public void setLast(Node last) {
this.last = last;
} public int getSize() {
return size;
} public void setSize(int size) {
this.size = size;
} @SuppressWarnings("unchecked")
public E getNode(int index) {
if(index>=size||index<){
throw new RuntimeException("Index out of bounds:"+index);
}
Node temp = first;
for (int i = ; i < index; i++) {
temp = temp.getNext();
}
return (E)temp.getElement();
} public void removeNode(int index) {
Node temp = first;
if (index < || index > size - ) {
throw new RuntimeException("Index number is illegal:" + index);
}
if (index == ) {
first = first.getNext();
first.setPrevious(null);
} else if (index == size - ) {
last = last.getPrevious();
last.setNext(null);
} else {
for (int i = ; i < index - ; i++) {
temp = temp.getNext();
}
temp.setNext(temp.getNext().getNext());
temp = temp.getNext().getNext();
temp.setNext(temp.getPrevious().getPrevious());
}
size--;
} @Override
public String toString() {
StringBuilder str = new StringBuilder();
str.append("[");
if(first!=null){
str.append(first);
Node temp=first;
while((temp=temp.getNext())!=null){
str.append(","+temp);
}
}
str.append("]");
return str.toString();
} }
package com.littlepage.linkedList;
/**
* 节点数据
* @author Littlepage
* @reference bjsxt.com
*
*/
public class Node {
private Node previous;
private Node next;
private Object element; public Node(Object element) {
this.element = element;
} public Node getPrevious() {
return previous;
} public void setPrevious(Node previous) {
this.previous = previous;
} public Node getNext() {
return next;
} public void setNext(Node next) {
this.next = next;
} public Object getElement() {
return element;
} public void setElement(Object element) {
this.element = element;
} @Override
public String toString() {
return element.toString();
}
}
package com.littlepage.linkedList;
/**
* 测试类
* @author Littlepage
* @reference bjsxt.com
*
*/
public class Test {
public static void main(String[] args) {
LittlePagesLinkedList<String> list=new LittlePagesLinkedList<>();
list.add("aa");
list.add("pp");
System.out.println(list);
}
}
Vector向量中大部分方法加了sychronized，保证线程安全