1 package net.bigwrok; 2 3 import java.util.ArrayList; 4 import java.util.Arrays; 5 import java.util.LinkedList; 6 import java.util.List; 7 import java.util.ListIterator; 8 9 public class CopyTest { 10 static void reverse(List<Integer> list) { 11 ListIterator<Integer> fwd = list.listIterator(); 12 ListIterator<Integer> rev = list.listIterator(list.size()); 13 int mid = list.size() / 2;// list.size() >> 1; 14 for (int i = 0; i < mid; i++) { 15 Integer tmp = fwd.next(); 16 fwd.set(rev.previous()); 17 rev.set(tmp); 18 } 19 } 20 static void reverse2(List<Integer> list) { 21 //仅仅输出 it.previous() ，第一次输出的元素index是 (size11 -1) 22 int size11 = list.size(); 23 ListIterator<Integer> it = list.listIterator(size11); 24 while (it.hasPrevious()) { 25 System.out.print (it.previous()+" , "); 26 } 27 System.out.println(); 28 } 29 30 public static void main(String[] args) { 31 List<Integer> src = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9); 32 List<Integer> dest = new LinkedList<Integer>(src); 33 34 System.out.println("source: " + src); 35 System.out.println("destination: " + dest); 36 37 reverse(dest); 38 //reverse2(dest); 39 System.out.println("source: " + src); 40 System.out.println("destination: " + dest); 41 42 43 44 } 45 46 }
结果
1 source: [1, 2, 3, 4, 5, 6, 7, 8, 9] 2 destination: [1, 2, 3, 4, 5, 6, 7, 8, 9] 3 source: [1, 2, 3, 4, 5, 6, 7, 8, 9] 4 destination: [9, 8, 7, 6, 5, 4, 3, 2, 1]