用java数组实现基本链表和可自扩充的链表

package com.tongji.szx.base;

import com.tongji.szx.baseDao.ListInterface;

public class ExtendList<T> implements ListInterface<T>{
 
 private T[] entry;
 private int length;
 private int capacity;
 private static final int BASE_LENGTH=10;
 
 /**
  * 默认的构造函数
  */
 public ExtendList(){
  this(BASE_LENGTH);
 }
 @SuppressWarnings("unchecked")
 /**
  * 提供一个初始链表长度的构造函数
  */
 public ExtendList(int intLength){
  if(intLength>0){
   this.length=intLength;
   this.capacity=intLength;
   entry=(T[])new Object[intLength];
  }else{
   this.length=BASE_LENGTH;
   this.capacity=BASE_LENGTH;
   entry=(T[])new Object[BASE_LENGTH];
  }
 }
 @Override
 /**
  * 在链表的末尾插入元素
  */
 public boolean add(T anEntry) {
  // TODO Auto-generated method stub
  try{
   if(length==capacity){
    copyEntry();
   }
   entry[length]=anEntry;
   length++;
   return true;
  }catch(Exception e){
   return false;
  }
 }
 
 @SuppressWarnings("unchecked")
 private void copyEntry(){
  T[] newEntry=entry;
  this.capacity*=2;
  entry=(T[])new Object[this.capacity];
  for(int index=0;index<newEntry.length;++index){
   entry[index]=newEntry[index];
  }
 }
 @Override
 public boolean add(int index, T anEntry) {
  // TODO Auto-generated method stub
  try{
   while(index>=capacity){
    copyEntry();
   }
   if(index<length){
    moveEntry(index,anEntry);
    length++;
    return true;
   }else{
    entry[index]=anEntry;
    //length+=(index);
    int sub=index-length+1;
    length+=sub;
    return true;
   }
  }catch(Exception e){
   return false;
  }
  //return false;
 }
 
 /**
  * 当插入位置在length之前时移动元素
  * @param index
  * @param anEntry
  */
 private boolean moveEntry(int aPosition,T anEntry){
  if(aPosition<length){
   for(int index=length-1;index>=aPosition;++index){
    entry[index+1]=entry[index];
   }
   entry[aPosition]=anEntry;
   return true;
  }
  return false;
 }

 @Override
 public boolean contains(T anEntry) {
  // TODO Auto-generated method stub
  for(T t:entry){
   if(t.equals(anEntry)){
    return true;
   }
  }
  return false;
 }

 @Override
 public T get(int index) {
  // TODO Auto-generated method stub
  if(index<length){
   return entry[index];
  }
  return null;
 }

 @Override
 public boolean isEmpty() {
  // TODO Auto-generated method stub
  return (length==0);
 }

 @Override
 public boolean isFull() {
  // TODO Auto-generated method stub
  return (length==capacity);
  //return false;
 }

 @Override
 public T remove(int index) {
  // TODO Auto-generated method stub
  if(index<length){
   T newEntry=entry[index];
   for(int i=index;i<length;++i){
    entry[i]=entry[i+1];
   }
   length--;
   return newEntry;
  }
  return null;
 }

 @Override
 public T replace(int index, T anEntry) {
  // TODO Auto-generated method stub
  if(index<length){
   T newEntry=entry[index];
   entry[index]=anEntry;
   return newEntry;
  }
  return null;
 }
 @Override
 public int getLength(){
  return length;
 }
 public int getCapacity(){
  return this.capacity;
 }
 public void Display(){
  for(int index=0;index<length;++index){
   if(entry[index]!=null){
    System.out.println(index+":"+entry[index].toString());
   }else{
    System.out.println(index+":"+"对象为空！");
   }
  }
 }
 
 public static void main(String[] args){
  System.out.println("====================");
  ExtendList<String> elst=new ExtendList<String>(5);
  elst.add("sunzhenxing");
  elst.add(10, "sunhailong");
  
  elst.Display();
  System.out.println(elst.getLength());
  System.out.println(elst.getCapacity());
  elst.remove(10);
  System.out.println(elst.getLength());
  elst.Display();
 }
 
 
 
 
 
}