Java集合类详解：ArrayList与Arrays/Collections操作示例

package com.tiantian;

import java.util.*;

public class JAVAContainer {

     public static void main(String[] args) throws Exception {
         //     ArrayList
         {
             ArrayList arraylist = new ArrayList();
             arraylist.add(0, "end");//指定索引加入值
             //     需注意的是，如果现有2个值，我加入索引为5的那么就会出现异常
             for (int i = 0; i < 2; i++) {
                 arraylist.add(i, String.valueOf(i));
             }
             System.out.println("ArrayList:");
             for (int i = 0; i < arraylist.size(); i++) {
                 System.out.print(arraylist.get(i) + ";");
             }
             arraylist.add("0");//直接加入值到ArrayList的最后
             arraylist.add("0");
             System.out.print(" ArrayList's lastIndexOf("0") is "
                     + arraylist.lastIndexOf("0"));
         }
         //     Arrays
         {
             String[] array = new String[] { "a", "b", "c" };
             List list = Arrays.asList(array);
             System.out.println(" Arrays:");
             for (int i = 0; i < list.size(); i++) {

                 System.out.print(list.get(i) + ";");
             }
             System.out.print(" Arrays's length is " + array.length);//打印数组的长度
         }
         //     Collections是一个全局元素，那里就可以用
         {
             String[] array = new String[] { "a", "b", "c" };
             List list = Arrays.asList(array);
             Collections.fill(list, "Fill");//用Fill填充全部元素,删除原来的元素
             System.out.println(" Collections:");
             for (int i = 0; i < list.size(); i++) {
                 System.out.print(list.get(i) + ";");
             }
             array = new String[] { "1", "2", "3" };
             List list2 = Arrays.asList(array);
             Collections.copy(list, list2);//拷贝list2的数据进list,删除list原来的元素
             System.out.println(" " + list);
             Collections.swap(list, 2, 1);//调换索引为1和2的元素的位置
             System.out.println(list);
         }
         // EventObject
         {
             String s = "hello";
             String s2 = s;
             EventObject eventobject = new EventObject(s);//一个准容器类型，确切的归类它不是容器
             System.out.println("EventObject:");
             System.out.println(eventobject.getSource());
             System.out.println(eventobject.equals(s2));
         }
         // HashMap