【Java 动态数据统计图】动态数据统计思路案例（动态，排序，动态数组（重点推荐））七（129）

需求：前端根据后端的返回数据：画统计图；

说明：
1.X轴为地域，Y轴为地域出现的次数；
2. 动态展示（有地域展示，没有不展示，且高低排序）

Demo案例：

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;public class day22 {public static void main(String[] args) {List<Map<String,Object>> list = new ArrayList<>();Map<String,Object> map1 = new HashMap<>();map1.put("region","西安");map1.put("num",1.0);Map<String,Object> map2 = new HashMap<>();map2.put("region","上海");map2.put("num",2.0);Map<String,Object> map3 = new HashMap<>();map3.put("region","北京");map3.put("num",3.0);Map<String,Object> map4 = new HashMap<>();map4.put("region","西安");map4.put("num",1.5);Map<String,Object> map5 = new HashMap<>();map5.put("region","西安");map5.put("num",2.5);Map<String,Object> map6 = new HashMap<>();map6.put("region","北京");map6.put("num",4.0);Map<String,Object> map7 = new HashMap<>();map7.put("region","成都");map7.put("num",1.0);Map<String,Object> map8 = new HashMap<>();map8.put("region","上海");map8.put("num",2.0);Map<String,Object> map9 = new HashMap<>();map9.put("region","上海");map9.put("num",2.5);Map<String,Object> map10 = new HashMap<>();map10.put("region","上海");map10.put("num",2.0);Map<String,Object> map11 = new HashMap<>();map11.put("region","长沙");map11.put("num",2.0);Map<String,Object> map12 = new HashMap<>();map12.put("region","苏州");map12.put("num",2.0);Map<String,Object> map13 = new HashMap<>();map13.put("region","江西");map13.put("num",2.0);Map<String,Object> map14 = new HashMap<>();map14.put("region","长沙");map14.put("num",2.0);Map<String,Object> map15 = new HashMap<>();map15.put("region","苏州");map15.put("num",2.0);list.add(map1);list.add(map2);list.add(map3);list.add(map4);list.add(map5);list.add(map6);list.add(map7);list.add(map8);list.add(map9);list.add(map10);list.add(map11);list.add(map12);list.add(map13);list.add(map14);list.add(map15);// Set：获取数组中的所有数据：去重Set<String> hashSet = new HashSet<>();for (int i = 0; i < list.size(); i++) {String region = String.valueOf(list.get(i).get("region"));hashSet.add(region);}String[] regionArr = new String[hashSet.size()];int[] valueSort = new int[hashSet.size()];// Set转数组if(list.size() > 0){regionArr = hashSet.toArray(new String[hashSet.size()]);}// 根据数组计算每个元素的数量；for (int i = 0; i < regionArr.length; i++) {for (int j = 0; j < list.size(); j++) {String s = String.valueOf(list.get(j).get("region"));if(regionArr[i].equals(s)){valueSort[i] = valueSort[i] + 1;}}}// 排序；BubblSortUtils.bubbleSortDescMultiple(valueSort,regionArr);List<Map<String,Object>> listFinal= new ArrayList<>();for (int i = 0; i < regionArr.length; i++) {Map<String,Object> map = new HashMap<>();map.put("title",regionArr[i]);map.put("value",valueSort[i]);listFinal.add(map);}System.out.println("listFinal:"+listFinal);}
}

测试输出：

listFinal:[{title=上海, value=4}, {title=西安, value=3}, {title=苏州, value=2}, {title=北京, value=2}, {title=长沙, value=2}, {title=江西, value=1}, {title=成都, value=1}]

案例二：

	public List<Map<String,Object>> getRevealData(HttpServletRequest request, Map<String, Object> paramMap) {List<Map<String,Object>> list = getCountData(request,paramMap);if(list.size() == 0){return null;}// 获取数据的类型；去重Set<String> hashSet = new HashSet<>();for (int i = 0; i < list.size(); i++) {String waysOfProblemReveal = String.valueOf(list.get(i).get("waysOfProblemReveal"));hashSet.add(waysOfProblemReveal);}String[] waysOfProblemArr = new String[hashSet.size()];int[] valueSort = new int[hashSet.size()];if(list.size() > 0){waysOfProblemArr = hashSet.toArray(new String[hashSet.size()]);}// 根据数组，计算每个元素的个数；for (int i = 0; i < waysOfProblemArr.length; i++) {for (int j = 0; j < list.size(); j++) {String s = String.valueOf(list.get(j).get("waysOfProblemReveal"));if(waysOfProblemArr[i].equals(s)){valueSort[i] = valueSort[i] + 1;}}}// 数组排序；BubblSortUtils.bubbleSortDescMultiple(valueSort,waysOfProblemArr);List<Map<String,Object>> listFinal= new ArrayList<>();for (int i = 0; i < waysOfProblemArr.length; i++) {Map<String,Object> map = new HashMap<>();map.put("title",waysOfProblemArr[i]);map.put("value",valueSort[i]);map.put("sortValue",waysOfProblemArr.length-i);listFinal.add(map);}return listFinal;}

postman接口测试：