springboot
import cn.hutool.core.io.IoUtil;
import cn.hutool.json.JSONConfig;
import cn.hutool.json.JSONUtil;
import com.itheima.pojo.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

@RestController
public class UserController {

@RequestMapping("/list")
public String list(){
    //1.加载并读取文件
    InputStream in = this.getClass().getClassLoader().getResourceAsStream("user.txt");
    ArrayList<String> lines = IoUtil.readLines(in, StandardCharsets.UTF_8, new ArrayList<>());
    
    //2.解析数据，封装成对象 --> 集合
    List<User> userList = lines.stream().map(line -> {
        String[] parts = line.split(",");
        Integer id = Integer.parseInt(parts[0]);
        String username = parts[1];
        String password = parts[2];
        String name = parts[3];
        Integer age = Integer.parseInt(parts[4]);
        LocalDateTime updateTime = LocalDateTime.parse(parts[5], DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));

        return new User(id, username, password, name, age, updateTime);
    }).collect(Collectors.toList());
    
    //3.响应数据
    //return JSONUtil.toJsonStr(userList, JSONConfig.create().setDateFormat("yyyy-MM-dd HH:mm:ss"));
    return userList;
}

}