Jacksonでjson文字列生成

package com.example.todo.api.todo;

import java.util.LinkedHashMap;
import java.util.Map;

import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonUtil {

    public static String createErrorMessageJson(String messageId, String message) {
        try {
            Map<String, String> map = new LinkedHashMap<>();
            map.put("messageId", messageId);
            map.put("message", message);
            ObjectMapper mapper = new ObjectMapper();
            return mapper.writeValueAsString(map);
        } catch (Exception e) {
            throw new RuntimeException("JSON生成失敗", e);
        }
    }
}

String json = JsonUtil.createErrorMessageJson("E002", "無効な入力です");
System.out.println(json);

実行例

{"messageId":"E002","message":"無効な入力です"}