Spring Boot中动态读取并处理更新的JSON文件

# 定义JSON文件的文件系统路径
# 在开发环境中，可以指向项目内部的resources目录
# 在生产环境中，应指向外部的绝对路径，例如：file:/opt/app/data/file.json
app.data.json-file-path=file:./src/main/resources/json/file.json

package com.example.demo.model;

import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.AllArgsConstructor;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Master {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private String value;
    // 根据您的JSON结构添加其他字段
}

package com.example.demo.Repository;

import com.example.demo.model.Master;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface MasterRepository extends CrudRepository<Master, Long> {
}

package com.example.demo.Services;

import com.example.demo.Repository.MasterRepository;
import com.example.demo.model.Master;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional; // 导入Transactional

import java.util.List;

@Service
public class MasterService {
    private final MasterRepository masterRepository;

    // 推荐使用构造器注入
    public MasterService(MasterRepository masterRepository) {
        this.masterRepository = masterRepository;
    }

    public Iterable<Master> list() {
        return masterRepository.findAll();
    }

    @Transactional // 确保批量保存操作在一个事务中
    public Iterable<Master> save(List<Master> masters) {
        // 实际应用中，您可能需要处理更新或删除旧数据，以避免重复或过时数据
        // 例如：先清空表或根据业务ID进行更新
        // masterRepository.deleteAll(); // 如果是全量更新
        return masterRepository.saveAll(masters);
    }

    @Transactional
    public Master save(Master master){
        return masterRepository.save(master);
    }
}

package com.example.demo.Services;

import com.example.demo.model.Master;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

@Service
public class JsonFileProcessor {

    private final MasterService masterService;
    private final ObjectMapper objectMapper;
    private final ResourceLoader resourceLoader;
    private final String jsonFilePath;

    // 使用构造器注入所有依赖和配置值
    public JsonFileProcessor(MasterService masterService,
                             ObjectMapper objectMapper,
                             ResourceLoader resourceLoader,
                             @Value("${app.data.json-file-path}") String jsonFilePath) {
        this.masterService = masterService;
        this.objectMapper = objectMapper;
        this.resourceLoader = resourceLoader;
        this.jsonFilePath = jsonFilePath;
    }

    @Scheduled(fixedRate = 90000) // 每90秒执行一次
    public void processAndUpdateData() {
        System.out.println("Scheduled task started: Reading JSON file from " + jsonFilePath);
        try {
            // 使用ResourceLoader获取资源
            Resource resource = resourceLoader.getResource(jsonFilePath);

            // 检查资源是否存在且可读
            if (!resource.exists()) {
                System.err.println("Error: JSON file not found at: " + jsonFilePath);
                return;
            }
            if (!resource.isReadable()) {
                System.err.println("Error: JSON file not readable at: " + jsonFilePath);
                return;
            }

            // 使用try-with-resources确保InputStream被正确关闭
            try (InputStream inputStream = resource.getInputStream()) {
                TypeReference<List<Master>> typeReference = new TypeReference<List<Master>>() {};
                List<Master> masters = objectMapper.readValue(inputStream, typeReference);

                if (masters != null && !masters.isEmpty()) {
                    System.out.println("Read " + masters.size() + " records from JSON. First item: " + masters.get(0));
                    masterService.save(masters);
                    System.out.println("Saved " + masters.size() + " records to database.");
                } else {
                    System.out.println("No records found in JSON file or file is empty.");
                }
            }
        } catch (IOException e) {
            System.err.println("Error processing JSON file '" + jsonFilePath +