Java List平均集合 Java 实现将List平均分成若干个集合

package com.example.springboottest.common.util;
 
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
 
import com.google.common.collect.Lists;
/**
 * List 工具类
 * @author Neo 
 * @date 2018年4月16日13:13:37
 */
public class ListUtils {
 
  /**
   * 将一个List均分成n个list,主要通过偏移量来实现的
   *
   * @param source 源集合
   * @param limit 最大值
   * @return
   */
  public static <T> List<List<T>> averageAssign(List<T> source, int limit) {
    if (null == source || source.isEmpty()) {
      return Collections.emptyList();
    }
    List<List<T>> result = new ArrayList<>();
    int listCount = (source.size() - 1) / limit + 1;
    int remaider = source.size() % listCount; // (先计算出余数)
    int number = source.size() / listCount; // 然后是商
    int offset = 0;// 偏移量
    for (int i = 0; i < listCount; i++) {
      List<T> value;
      if (remaider > 0) {
        value = source.subList(i * number + offset, (i + 1) * number + offset + 1);
        remaider--;
        offset++;
      } else {
        value = source.subList(i * number + offset, (i + 1) * number + offset);
      }
      result.add(value);
    }
    return result;
  }
  public static void main(String[] args) {
    List list = new ArrayList();
    for (int i = 0; i < 65; i++) {
      list.add(i);
    }
    List<List> result = averageAssign(list, 15);
    result.forEach(l -> {
      l.forEach(i ->
          System.out.print(i + "\t")
      );
      System.out.println();
    });
    System.out.println("====================================================");
    result = averageAssign(list, 20);
    result.forEach(l -> {
      l.forEach(i ->
          System.out.print(i + "\t")
      );
      System.out.println();
    });
 
    System.out.println("====================================================");
    // Guava 实现不平均分组
    result = Lists.partition(list ,100);
        result.forEach(l -> {
      l.forEach(i ->
          System.out.print(i + "\t")
      );
      System.out.println();
    });
  }
}

/**
 * @author caishen
 * @version 1.0
 * @className CollectionUtils
 * @date 2019/5/23 11:54
 * 自分で書いたコードの各行を担当する
 * @dis 切割list工具类
 **/
public class CollectionUtils {

  public static <T> List<List<T>> divide(List<T>origin , int size){
    if(Assert.isEmpty(origin)){
      return Collections.emptyList();
    }

    int block = (origin.size() + size -1) / size;
    return IntStream.range(0,block).
        boxed().map(i->{
          int start = i*size;
          int end = Math.min(start + size,origin.size());
          return origin.subList(start,end);
    }).collect(Collectors.toList());
  }

  public static void main(String[] args) {
    System.out.println(divide(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10), 3));
  }
}