java list存储信息平均值 java用list集合存储学生信息并算出成绩平均值操作

package com.ine.tool;

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

/**
 * 计算平均值，去除不合理的数据
 * 
 * @author Ro
 * 
 */
public class AverageTool
{
  /**
   * 主方法
   */
  public static int getAverage(String str_int_arr)
  {
    int[] int_arr = stringToIntWhitSort(str_int_arr.split(","));
    if (1 < int_arr.length)
    {
      return getAverageByGoodList(getGoodListByBaseList(getBaseListByIntArray(int_arr)));
    }
    return Integer.parseInt(str_int_arr);
  }

  /**
   * 将String数组转换为int数组
   */
  private static int[] stringToIntWhitSort(String[] arrs)
  {
    int[] ints = new int[arrs.length];
    for (int i = 0; i < arrs.length; i++)
    {
      ints[i] = Integer.parseInt(arrs[i]);
    }

    Arrays.sort(ints);
    System.out.println("ints：" + Arrays.toString(ints));
    return ints;
  }

  /**
   * 将int数组根据计算的基准值按块分离
   */
  private static List<List<Integer>> getBaseListByIntArray(int[] int_arr)
  {
    List<List<Integer>> list = new ArrayList<List<Integer>>();
    list.add(new ArrayList<Integer>());

    int list_index = 0;
    int average_flag = 0;
    int sum_temp = 0;

    for (int i : int_arr)
    {
      sum_temp += i;
    }
    average_flag = sum_temp / int_arr.length;

    System.out.println("average_flag：" + average_flag);
    for (int i = 0; i < int_arr.length - 1; i++)
    {
      if (average_flag >= Math.abs(int_arr[i] - int_arr[i + 1]))
      {
        list.get(list_index).add(int_arr[i]);
      }
      else
      {
        list.get(list_index++).add(int_arr[i]);
        list.add(new ArrayList<Integer>());
      }

      if ((i + 2) == int_arr.length)
      {
        list.get(list_index).add(int_arr[i + 1]);
      }
    }
    System.out.println("getBaseListByIntArray：" + list.toString());
    return list;
  }

  /**
   * 筛选留下数据最多的块
   */
  private static List<List<Integer>> getGoodListByBaseList(
      List<List<Integer>> list)
  {
    if (1 < list.size())
      for (int i = 1; i < list.size(); i++)
      {
        if (list.get(0).size() != list.get(i).size())
        {
          if (list.get(0).size() < list.get(i).size())
          {
            list.remove(0);
          }
          else
          {
            list.remove(i);
          }
          i--;
        }
      }
    System.out.println("getGoodListByBaseList：" + list.toString());
    return list;
  }

  /**
   * 将块计算平均值，如果数据大于两位，则个位四舍五入
   */
  private static int getAverageByGoodList(List<List<Integer>> good_list)
  {
    int average = 0;
    int sum_temp = 0;
    int sum_index = 0;
    for (List<Integer> t_list : good_list)
    {
      for (int i : t_list)
      {
        sum_temp += i;
        sum_index += 1;
      }
    }
    average = sum_temp / sum_index;
    if (10 < average)
      average = (average + 5) / 10 * 10;
    return average;
  }
}