Map对象如何转换为一个POJO对象呢?

Map是我们日常开发中，经常使用的一个集合对象
Pojo是我们日常开发中的一个实体对象

那么如何将Map集合对象中 key ,value的形式转换为Pojo对象呢?

Map转pojo的实现思路

将Map对象转换为JSON对象
将JSON对象转换为pojo实体对象
    使用以上操作，即可实现Map转POJO的效果

package com.jd;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import org.springframework.http.converter.json.JsonbHttpMessageConverter;

import java.util.HashMap;
import java.util.Map;

/**
 * java265.com map转换为 pojo对象
 *
 * */
public class MapToPoJo {


    public static void main(String[] args) throws Exception {

        Map<String, String> inputMap = new HashMap<>();
        inputMap.put("name", "java265.com");
        inputMap.put("email", "admin@java265.com");

        ObjectMapper objectMapper = new ObjectMapper();

        JsonConverter converter = new JsonConverter(objectMapper);

        // Convert map to POJO
        UserInfo user = converter.convertToPojo(inputMap,UserInfo.class);

        System.out.println("user=======>:"+user);

    }
}


class UserInfo {
    public String name;
    public String email;

    @Override
    public String toString() {
        return "UserInfo{" +
                "name='" + name + '\'' +
                ", email='" + email + '\'' +
                '}';
    }
}


class JsonConverter {
    private final ObjectMapper objectMapper;

    public JsonConverter(ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
    }

    public <T> T convertToPojo(Map<String, String> flatMap, Class<T> clazz) throws Exception {
        ObjectNode root = objectMapper.createObjectNode();
        for (Map.Entry<String, String> entry : flatMap.entrySet()) {
            setNestedValue(root, entry.getKey(), entry.getValue());
        }
        return objectMapper.treeToValue(root, clazz);
    }

    private void setNestedValue(ObjectNode node, String key, String value) {
        String[] parts = key.split("\\.");
        ObjectNode current = node;
        for (int i = 0; i < parts.length - 1; i++) {
            String part = parts[i];
            if (part.matches(".*\\[\\d+\\]")) {
                String arrayPart = part.replaceAll("\\[\\d+\\]", "");
                int index = Integer.parseInt(part.replaceAll("[^\\d]", ""));
                ArrayNode arrayNode = (ArrayNode) current.get(arrayPart);
                if (arrayNode == null) {
                    arrayNode = current.putArray(arrayPart);
                }
                while (arrayNode.size() <= index) {
                    arrayNode.add(objectMapper.createObjectNode());
                }
                current = (ObjectNode) arrayNode.get(index);
            } else {
                ObjectNode child = (ObjectNode) current.get(part);
                if (child == null) {
                    child = current.putObject(part);
                }
                current = child;
            }
        }
        current.put(parts[parts.length - 1], value);
    }
}