按 JSON 数组的唯一 ID 分组答案

【问题标题】：Grouping by Unique ID for JSON Array按 JSON 数组的唯一 ID 分组
【发布时间】：2023-02-18 02:55:08
【问题描述】：

块引用

我有以下 JSON 输入请求，必须按以下方式分组ID范围。

输入：

[
    {
        "ID": "1234",
        "CustomerName": "KUMAR",
        "BranchName": "HARBOUR",
        "SchemeName": "GOLD",
        "MobileNumber": "123456789",
        "CustomerType": "PRIMARY",
        "DedupeFound" : "NO"
        
    },
    {
        "ID": "1234",
        "CustomerName": "SEAN",
        "BranchName": "HARBOUR",
        "SchemeName": "GOLD",
        "MobileNumber": "123456789",
        "CustomerType": "SECONDARY",
        "DedupeFound" : "YES"
    },
    {
        "ID": "5678",
        "CustomerName": "MARK",
        "BranchName": "CANTONMENT",
        "SchemeName": "DIAMOND",
        "MobileNumber": "123456789",
        "CustomerType": "PRIMARY",
        "DedupeFound" : "NO"
    },
    {
        "ID": "5678",
        "CustomerName": "STEVE",
        "BranchName": "CANTONMENT",
        "SchemeName": "DIAMOND",
        "MobileNumber": "123456789",
        "CustomerType": "SECONDARY",
        "DedupeFound" : "YES"
    }
]

上面的请求需要按照下面的方式进行改造

首先根据 ID 标签对记录进行分组，只需要显示主 ID 的详细信息

在 ID 记录详细信息中。我有两个客户的 DedupeDetails 数组。

输出

[
    {
        "ID": "1234",
        "CustomerName": "KUMAR",           // Only Primary Customer Details for the 
        "BranchName": "HARBOUR",           //  ID Tag to be displayed here
        "SchemeName": "GOLD",
        "MobileNumber": "123456789"
        "DedupeDetails": [
            {
                "CustomerType": "PRIMARY"
                "CustomerName": "KUMAR",
                "DedupeFound" : "NO"
            },
            {
                "CustomerType": "SECONDARY"
                "CustomerName": "SEAN",
                "DedupeFound" : "YES"
            }
        ]
    },
    {
        "ID": "5678",
        "CustomerName": "MARK",
        "BranchName": "CANTONMENT",
        "SchemeName": "DIAMOND",
        "MobileNumber": "123456789"
        "DedupeDetails": [
            {
                "CustomerType": "PRIMARY"
                "CustomerName": "MARK",
                "DedupeFound" : "NO"
            },
            {
                "CustomerType": "SECONDARY"
                "CustomerName": "STEVE",
                "DedupeFound" : "YES"
            }
        ]
    }
]

我已经开始使用 apache camel 中的 java 代码。我能够成功地将 json 字符串映射到对象列表。我仍然对如何进行分组以实现输出一无所知。

注意：我是 java 的新手。强烈建议任何建议/更正。

爪哇

package com.mycompany.Login;

import java.util.List;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.sql.Timestamp;
import java.io.File;
import java.io.PrintWriter;
import java.sql.Time;
import com.mycompany.Login.*;
import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.mycompany.Dedupe.DedupeRoot.DedupeRes;




public class LoginMapping implements Processor{
    public void process(Exchange ex)throws Exception{ 
    
        try {   
        
           
            String responseString = {Input mentioned in post};          
            ObjectMapper mapper = new ObjectMapper();
            mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);         
            List<DedupeRes> dedupe = Arrays.asList(mapper.readValue(responseString, DedupeRes[].class));  
            int total = dedupe.size();          
            if (total > 0)
            {               
                for (int i = 0; i < total; i++) {                   
                    
                }               
            }
    
     ex.getIn().setBody(responseString);
        }       
        catch(Exception e) {
            ex.getIn().setHeader("ExpMsg", "Undefined");
            throw e;
        }   
    
}
}

【问题讨论】：

标签： java

【解决方案1】：

完整的代码实现，试试吧。

public class T {

    private static final ObjectMapper mapper = new ObjectMapper();

    static {
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    }

    public static <T> List<T> parseObjectList(String json, Class<T> clazz) {
        try {
            return mapper.readValue(
                    json,
                    TypeFactory.defaultInstance().constructParametricType(ArrayList.class, clazz)
            );
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static <T> String toJsonString(T t) {
        try {
            return mapper.writeValueAsString(t);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static void main(String[] args) {
        try {
            String responseString = "[{"ID":"1234","CustomerName":"KUMAR","BranchName":"HARBOUR","SchemeName":"GOLD","MobileNumber":"123456789","CustomerType":"PRIMARY","DedupeFound":"NO"},{"ID":"1234","CustomerName":"SEAN","BranchName":"HARBOUR","SchemeName":"GOLD","MobileNumber":"123456789","CustomerType":"SECONDARY","DedupeFound":"YES"},{"ID":"5678","CustomerName":"MARK","BranchName":"CANTONMENT","SchemeName":"DIAMOND","MobileNumber":"123456789","CustomerType":"PRIMARY","DedupeFound":"NO"},{"ID":"5678","CustomerName":"STEVE","BranchName":"CANTONMENT","SchemeName":"DIAMOND","MobileNumber":"123456789","CustomerType":"SECONDARY","DedupeFound":"YES"}]";
            List<DedupeRes> list = parseObjectList(responseString, DedupeRes.class);
            if (list != null && !list.isEmpty()) {
                Map<String, List<DedupeRes>> map = list.stream().collect(Collectors.groupingBy(DedupeRes::getID));
                List<Res> resList = new ArrayList<>();
                map.forEach((k, v) -> resList.add(listToRes(v)));
                responseString = toJsonString(resList);
                System.out.println(responseString);
            }
        } catch (Exception e) {
            // xx
            e.printStackTrace();
        }
    }

    private static Res listToRes(List<DedupeRes> list) {
        Res res = new Res();
        res.setDedupeDetails(new ArrayList<>());
        for (DedupeRes dedupeRes : list) {
            if (Objects.equals("PRIMARY", dedupeRes.getCustomerType())) {
                // if you used spring -> BeanUtils.copyProperties(dedupeRes, res);
                res.setID(dedupeRes.getID());
                res.setBranchName(dedupeRes.getBranchName());
                res.setCustomerName(dedupeRes.getCustomerName());
                res.setMobileNumber(dedupeRes.getMobileNumber());
                res.setSchemeName(dedupeRes.getSchemeName());
            }
            DedupeDetails details = new DedupeDetails();
            //
            BeanUtils.copyProperties(dedupeRes, details);
            res.getDedupeDetails().add(details);
        }
        return res;
    }

    @Data
    private static class DedupeRes {
        @JsonProperty("ID")
        private String ID;
        @JsonProperty("CustomerName")
        private String CustomerName;
        @JsonProperty("BranchName")
        private String BranchName;
        @JsonProperty("SchemeName")
        private String SchemeName;
        @JsonProperty("MobileNumber")
        private String MobileNumber;
        @JsonProperty("CustomerType")
        private String CustomerType;
        @JsonProperty("DedupeFound")
        private String DedupeFound;
    }

    @Data
    private static class Res {
        @JsonProperty("ID")
        private String ID;
        @JsonProperty("CustomerName")
        private String CustomerName;
        @JsonProperty("BranchName")
        private String BranchName;
        @JsonProperty("SchemeName")
        private String SchemeName;
        @JsonProperty("MobileNumber")
        private String MobileNumber;
        @JsonProperty("dedupeDetails")
        private List<DedupeDetails> dedupeDetails;
    }

    @Data
    private static class DedupeDetails {
        @JsonProperty("CustomerType")
        private String CustomerType;
        @JsonProperty("CustomerName")
        private String CustomerName;
        @JsonProperty("DedupeFound")
        private String DedupeFound;
    }
}

领事。

[{"ID":"1234","CustomerName":"KUMAR","BranchName":"HARBOUR","SchemeName":"GOLD","MobileNumber":"123456789","dedupeDetails":[{"CustomerType":"PRIMARY","CustomerName":"KUMAR","DedupeFound":"NO"},{"CustomerType":"SECONDARY","CustomerName":"SEAN","DedupeFound":"YES"}]},{"ID":"5678","CustomerName":"MARK","BranchName":"CANTONMENT","SchemeName":"DIAMOND","MobileNumber":"123456789","dedupeDetails":[{"CustomerType":"PRIMARY","CustomerName":"MARK","DedupeFound":"NO"},{"CustomerType":"SECONDARY","CustomerName":"STEVE","DedupeFound":"YES"}]}]

【讨论】：

【解决方案2】：

首先你必须创建DedupeDetail类：

public class DedupeDetail {

    String CustomerType;
    String CustomerName;
    String DedupeFound;

    public DedupeDetail(String customerType, String customerName, String dedupeFound) {
        CustomerType = customerType;
        CustomerName = customerName;
        DedupeFound = dedupeFound;
    }
}

然后用转换器创建DedupeResultFinal：

public class DedupeResultFinal {

    String ID;
    String CustomerName;
    String BranchName;
    String SchemeName;
    String MobileNumber;
    List<DedupeDetail> DedupeDetails;

    public DedupeResultFinal() {
    }

    public DedupeResultFinal(List<DedupeDetail> dedupeDetails) {
        DedupeDetails = dedupeDetails;
    }// ... other constructor and getter and setter

    public static DedupeResultFinal convertToFinal(HashMap<String, String> dedupeRes){
        DedupeResultFinal dedupeResultFinal = new DedupeResultFinal();

        dedupeResultFinal.setBranchName(dedupeRes.get("BranchName"));
        dedupeResultFinal.setCustomerName(dedupeRes.get("CustomerName"));
        dedupeResultFinal.setID(dedupeRes.get("ID"));
        dedupeResultFinal.setMobileNumber(dedupeRes.get("MobileNumber"));
        dedupeResultFinal.setSchemeName(dedupeRes.get("SchemeName"));

        return dedupeResultFinal;

    }
}

然后你的方法必须是这样的：

   public static void main(String[] args) {
        try {

            String responseString = {Input mentioned in post};
            ObjectMapper mapper = new ObjectMapper();
            mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
            List<HashMap<String, String>> dedupe = mapper.readValue(responseString, new ArrayList<String>().getClass());
            Map<String, DedupeResultFinal> map = new HashMap<>();

            for (HashMap<String, String> dedupeRes : dedupe) {
                if (map.get(dedupeRes.get("ID")) != null){
                    DedupeDetail dedupeDetail = new DedupeDetail(dedupeRes.get("CustomerType"), dedupeRes.get("CustomerName"), dedupeRes.get("DedupeFound"));
                    map.get(dedupeRes.get("ID")).getDedupeDetails().add(dedupeDetail);
                }else {
                    DedupeDetail dedupeDetail =  new DedupeDetail(dedupeRes.get("CustomerType"), dedupeRes.get("CustomerName"), dedupeRes.get("DedupeFound"));
                    DedupeResultFinal dedupeResultFinal = DedupeResultFinal.convertToFinal(dedupeRes);
                    List<DedupeDetail> dedupeDetails = new ArrayList<>();
                    dedupeDetails.add(dedupeDetail);
                    dedupeResultFinal.setDedupeDetails(dedupeDetails);

                    map.put(dedupeRes.get("ID"), dedupeResultFinal);
                }
            }

           List<DedupeResultFinal> finalDedup = map.values().stream().collect(Collectors.toList());

            System.out.println(finalDedup);
        }
        catch(Exception e) {
            e.printStackTrace();
        }
    }

【讨论】：

感谢 hani 的解决方案。但是我在尝试构建 jar 时遇到了这个错误。不兼容的类型：java.util.List<java.lang.Object> 无法转换为 java.util.List<com.Veritas.Test.DedupeResultFinal>
好吧，你先把 List 放在上层，然后再转换到下层。所以当你得到列表时，你的列表是 List<Object> 并且在迭代之后，你必须将每个成员转换为 DedupeResultFinal。

【解决方案3】：

您可以使用 JSON 库，例如约森做改造。

https://github.com/octomix/josson

反序列化

Josson josson = Josson.fromJsonString(yourJsonString);

方法一

从根节点开始查找每组的主记录。

JsonNode node = josson.getNode(
    "group(ID, DedupeDetails:map(CustomerType, CustomerName, DedupeFound))@" +
    ".let($id:ID, $pri:$.[ID=$id & CustomerType='PRIMARY'])" +
    ".field($pri.CustomerName, $pri.BranchName, $pri.SchemeName, $pri.MobileNumber)");

System.out.println(node.toPrettyString());

方法二

查找每个组中的主要记录。

JsonNode node = josson.getNode(
    "group(ID)@" +
    ".let($pri: elements[CustomerType='PRIMARY'])" +
    ".field($pri.CustomerName, $pri.BranchName, $pri.SchemeName, $pri.MobileNumber," +
    "       elements:, DedupeDetails:elements.map(CustomerType, CustomerName, DedupeFound))");

System.out.println(node.toPrettyString());

方法三

使用 mergeObjects() 而不是 let() 来完成任务。

JsonNode node = josson.getNode(
    "group(ID)@" +
    ".mergeObjects(" +
    "  elements[CustomerType='PRIMARY'].map(ID, CustomerName, BranchName, SchemeName, MobileNumber)," +
    "  map(DedupeDetails:elements.map(CustomerType, CustomerName, DedupeFound))" +
    ")");

System.out.println(node.toPrettyString());

【讨论】：