【列表操作】Java 实现 List 列表按照属性中的参数首字母进行排序

说明

选取数据过多,导致前台页面杂乱,采用首字母分类,优化用户体验,下面是 java 实现 List 按字母分类的方法,代码是全的,大家可以复制下来运行看看结果,希望可以帮到大家,有什么不懂的地方,在评论区留言交流!

测试入口类:Test.java

import com.google.gson.Gson;

import java.util.*;

/**
 * 测试入口 
 * @author Moonce
 */
 
 
public class Test {

   public static void main(String[] args) {  
        SortUtil obj1 = new SortUtil();
        //获取默认数据
	  List list= getTestData();
      //调用分类方法,返回map结果,结果格式:{A=[], B=[], C=[], D=[], E=[Symptom{id=3, typeId=0, name='恶心', remark='null'}], F=[], G=[], H=[], I=[], J=[], K=[], L=[], M=[], N=[], O=[Symptom{id=4, typeId=0, name='呕吐', remark='null'}], P=[], Q=[], R=[], S=[], T=[Symptom{id=1, typeId=0, name='头晕', remark='null'}, Symptom{id=2, typeId=0, name='头疼^', remark='null'}], U=[], V=[], W=[], X=[], Y=[], Z=[], 0=[]}
	Map map=  obj1.sortSymptom(list);
      System.out.println("Map输出结果:"+map);
      //循环按照类别输出列表
	  for (Map.Entry entry : map.entrySet()) {
         List symptoms = (List) entry.getValue();
         System.out.println(entry.getKey() +":" + symptoms);
      }
  // 用Gson转化为Json格式,结果格式:{"A":[],"B":[],"C":[],"D":[],"E":[{"id":3,"typeId":0,"name":"恶心"}],"F":[],"G":[],"H":[],"I":[],"J":[],"K":[],"L":[],"M":[],"N":[],"O":[{"id":4,"typeId":0,"name":"呕吐"}],"P":[],"Q":[],"R":[],"S":[],"T":[{"id":1,"typeId":0,"name":"头晕"},{"id":2,"typeId":0,"name":"头疼^"}],"U":[],"V":[],"W":[],"X":[],"Y":[],"Z":[],"0":[]}
	Gson gson = new Gson();
      System.out.println("Json输出结果:"+gson.toJson(map));/**/

  }

   /**
 * 自定义测试默认数据 * @return
  */
  private static List getTestData() {
      List list=new ArrayList();
      Symptom symptom = new Symptom();
      symptom.setName("头晕");
      symptom.setId(1L);
      list.add(symptom);
      symptom = new Symptom();
      symptom.setName("头疼^");
      symptom.setId(2L);
      list.add(symptom);
      symptom = new Symptom();
      symptom.setName("恶心");
      symptom.setId(3L);
      list.add(symptom);
      symptom = new Symptom();
      symptom.setId(4L);
      symptom.setName("呕吐");
      list.add(symptom);
      return list;
   }

}

首字母分类工具类:SortUtil.java

package com.jeesite.test;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 症状按首字母分类方法 
 * @author Moonce
 */
 public class SortUtil {
    public SortUtil() {

    }
   private final static String[] CAPITALIZATION_TABLE =
            {
                    "A", "B", "C", "D", "E", "F", "G", "H", "I",
                    "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "0"
  };
    //字母Z使用了两个标签，这里有２７个值
 //i, u, v都不做声母, 跟随前面的字母  
   private char[] chartable =
            {
                    '啊', '芭', '擦', '搭', '蛾', '发', '噶', '哈', '哈',
                    '击', '喀', '垃', '妈', '拿', '哦', '啪', '期', '然',
                    '撒', '塌', '塌', '塌', '挖', '昔', '压', '匝', '座'
  };
    private char[] alphatableb =
            {
                    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I',
                    'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
  };
    private char[] alphatables =
            {
                    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
                    'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
  };
    private int[] table = new int[27];  //初始化
  {
        for (int i = 0; i < 27; ++i) {
            table[i] = gbValue(chartable[i]);
        }
    }

    /**
 * 主函数,输入字符,得到他的声母, * 英文字母返回对应的大小写字母 * 其他非简体汉字返回 '0'  按参数 
 * @param ch 首字母
 * @param type b 大写 ,其他默认小写
 * @return
  */
  public char Char2Alpha(char ch,String type) {
        if (ch >= 'a' && ch <= 'z')
            return (char) (ch - 'a' + 'A');//为了按字母排序先返回大写字母
 // return ch;  if (ch >= 'A' && ch <= 'Z')
            return ch;

        int gb = gbValue(ch);
        if (gb < table[0])
            return '0';

        int i;
        for (i = 0; i < 26; ++i) {
            if (match(i, gb))
                break;
        }

        if (i >= 26){
            return '0';}
        else{
            if("b".equals(type)){//大写
  return alphatableb[i];
            }else{//小写
  return alphatables[i];
            }
        }
    }

    /**
 * 根据一个包含汉字的字符串返回一个汉字拼音首字母的字符串 
 * @param SourceStr 字符串
 * @param type 返回类型
 * @return
  */
  public String String2Alpha(String SourceStr,String type) {
        String Result = "";
        int StrLength = SourceStr.length();
        int i;
        try {
            for (i = 0; i < StrLength; i++) {
                Result += Char2Alpha(SourceStr.charAt(i),type);
            }
        } catch (Exception e) {
            Result = "";
        }
        return Result;
    }

    /**
 * 根据一个包含汉字的字符串返回第一个汉字拼音首字母的字符串 
 * @param SourceStr 字符串
 * @param type 返回类型
 * @return
  */
  public String String2AlphaFirst(String SourceStr,String type) {
        String Result = "";
        try {
            Result += Char2Alpha(SourceStr.charAt(0),type);
        } catch (Exception e) {
            Result = "";
        }
        return Result;
    }
    private boolean match(int i, int gb) {
        if (gb < table[i])
            return false;
        int j = i + 1;

        //字母Z使用了两个标签
	while (j < 26 && (table[j] == table[i]))
            ++j;
        if (j == 26)
            return gb <= table[j];
        else
   return gb < table[j];
    }

    /**
 * 取出汉字的编码 
 * @param ch
  * @return
  */
  private int gbValue(char ch) {
        String str = new String();
        str += ch;
        try {
            byte[] bytes = str.getBytes("GBK");
            if (bytes.length < 2)
                return 0;
            return (bytes[0] << 8 & 0xff00) + (bytes[1] &
                    0xff);
        } catch (Exception e) {
            return 0;
        }
    }

    /**
 * 症状列表分类方法 
 * @param list
  * @return
  */
  public Map sortSymptom(List list){
        Map map=new HashMap();
        List arraylist=new ArrayList();

        for(String a:CAPITALIZATION_TABLE){
            for(int i=0;i//为了排序都返回大写字母
	if(a.equals(String2AlphaFirst(list.get(i).getName().toString(),"b"))){
                    arraylist.add(list.get(i));
                }
            }

            map.put(a,arraylist);
            arraylist=new ArrayList();
        }
        return map;
    }
}

实体类:Symptom.java

package com.jeesite.test;

/**
 * 症状实体类 
 * @author Moonce
 */public class Symptom {
    private long id;

    private long typeId;

    private String name;

    private String remark;

    public Symptom() {
    }

    @Override
  public String toString() {
        return "Symptom{" +
                "id=" + id +
                ", typeId=" + typeId +
                ", name='" + name + '\'' +
                ", remark='" + remark + '\'' +
                '}';
    }

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public long getTypeId() {
        return typeId;
    }

    public void setTypeId(long typeId) {
        this.typeId = typeId;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getRemark() {
        return remark;
    }

    public void setRemark(String remark) {
        this.remark = remark;
    }
}

参考

java 中文首字母分组，排序