java List分批处理

 1 package com.example.demo;
 2 import com.google.common.collect.Lists;
 3 import java.util.ArrayList;
 4 import java.util.List;
 5 public class Test {
 6     public static void main(String[] args) {
 7         List<Integer> list = new ArrayList<>();
 8         for (int i = 0; i < 1500; i++) {
 9             list.add(i);
10         }
11         newBatchProcessing(list);
12         //谷歌工具包里的 Lists.partition
13         oldBatchProcessing(list);
14         //传统切割
15     }
16     public static void newBatchProcessing(List<Integer> numList) {
17         List<List<Integer>> lists = Lists.partition(numList, 1000);
18         for (List<Integer> list : lists) {
19             System.out.println(list);
20             //这里就可以分批对数据进行处理了
21         }
22     }
23     /**
24  * 传统方法分批
25  */
26     public static void oldBatchProcessing(List<Integer> list){
27         int listSize = list.size();
28         int toIndex = 1000;
29         for (int i = 0; i< list.size(); i += 1000){
30             if(i + 1000 > listSize){
31                 //作用为toIndex最后没有900条数据则剩余几条newList中就装几条
32                 toIndex = listSize - i;
33             }
34             List<Integer> newList = list.subList(i, i + toIndex);
35             //分批数据做具体处理
36             System.out.println(newList);
37         }
38     }
39 }