java list泛型简单的几种转换

1. List<String> 转 List<integer> 、List<Long>

1 import java.util.ArrayList;
 2 import java.util.List;
 3 import java.util.stream.Collectors;
 4 
 5 public class Test1 {
 6     public static void main(String []args){
 7         //List<String>
 8         List<String> listString =new ArrayList();
 9         listString.add("1111");
10         listString.add("2222");
11         listString.add("3333");
12 
13         //listString 转List<Integer>
14         List<Integer> listInteger = listString.stream().mapToInt(Integer::parseInt).boxed().collect(Collectors.toList());
15 
16         //listString 转List<Long>
17         List<Long> listLong = listString.stream().mapToLong(Long::parseLong).boxed().collect(Collectors.toList());
18 
19     }
20 }

2. List<Object> 转 List<String>

package cn.dotfashion.soa.ops.job;

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


public class Test12 {
    public static void main(String []args){
        //List<Object>
        List<Object> listObject =new ArrayList<>();
        listObject.add("1111");
        listObject.add("2222");
        listObject.add("3333");
        
       //List<Object> 转 List<String>
        List<String> listString = Arrays.asList(listObject.toArray(new String[listObject.size()]));

    }
}