对象数组转换为List

将对象数组转换为List,空类型安全。

import java.util.ArrayList; 
   
import java.util.Arrays; 
   
import java.util.List; 
   

/** 
* 对象数组转换为List 
* 
* @author leizhimin 2010-4-29 19:08:12 
*/ 
   
public 
   class TestArray { 
   
         
   public 
   static 
   void main(String[] args) { 
   
                String[] a1 = { 
   "a", 
   "b", 
   "c"}; 
   
                String[] a2 = {}; 
   

                List s1 = array2List(a1); 
   
                List s2 = array2List(a2); 
   

                List s3 = array2List2(a1); 
   
                List s4 = array2List2(a2); 
   

                List s5 = array2List( 
   null); 
   
                List s6 = array2List2( 
   null); 
   


                System.out.println(s1.size()); 
   
                System.out.println(s2.size()); 
   
                System.out.println(s3.size()); 
   
                System.out.println(s4.size()); 
   
                System.out.println(s5.size()); 
   
                System.out.println(s6.size()); 
   
        } 
   

         
   /** 
         * 数组转换为List(不推荐使用) 
         * 
         * @param arr 数组 
         * @return List 
         */ 
   
         
   public 
   static List array2List(Object[] arr) { 
   
                List list = 
   new ArrayList(); 
   
                 
   if (arr == 
   null) 
   return list; 
   
                 
   for ( 
   int i = 0; i < arr.length; i++) { 
   
                        list.add(arr[i]); 
   
                } 
   
                 
   return list; 
   
        } 
   

         
   /** 
         * 数组转换为List(推荐使用) 
         * 
         * @param arr 数组 
         * @return List 
         */ 
   
         
   public 
   static List array2List2(Object[] arr) { 
   
                List list = 
   new ArrayList(); 
   
                 
   if (arr == 
   null) 
   return list; 
   
                list = Arrays.asList(arr); 
   
                 
   return list; 
   
        } 
   
}

3 
   
0 
   
3 
   
0 
   
0 
   
0 
   

Process finished with exit code 0