Java 根据订单号下载多张图片

  
    @GetMapping("/testDowload")
    public R dowloaImageGraceFully(@RequestParam("orderId") String orderId) {
        //本地路径 存储下载图片的路径
        String storePath = "C:/Users/Public/Pictures/img";

        List listStr = new ArrayList<>();
        //获取图片路径 从文件服务器中
        //根据订单号 从数据库中 查询 图片的id
        List list = orderMapper.downloadHtById(orderId);
        if (list == null){
            return R.ok("合同还未上传，请联系管理员！");
        }else {
            for (int i = 0; i < list.size(); i++) {
                String managementrightContract = list.get(i).getManagementrightContract();
                //id可能有多个,所以在这里进行分开查询
                String [] arr = managementrightContract.split(",");
                if (arr.length>0){
                    //根据id 从文件服务器中获取到相应的图片存储路径
                    for (int j = 0; j < arr.length; j++) {
                        IaFileStore iaFileStore = iaFileStoreMapper.selectOne(new QueryWrapper().eq("id", arr[j]));
                        if (null ==iaFileStore){
                            return R.ok("下载失败!");
                        }else {
                            IaFiles iaFiles = fileService.getOne(new QueryWrapper().eq("file_name",iaFileStore.getName()));
                            //将获取出来的图片路径存放到list中
                            listStr.add(fileService.getFileUrl(iaFiles.getUuid()));
                            //也可以将以下方法放在这里,就可以减少使用list转换,在这里我就不改了

                        }

                    }
                }

            }
        }
        //将list中的的数据拿出来转换为 字符串 (这里也可以放再上面.不用存储到list中)
        for (int i = 0; i < listStr.size(); i++) {
            String a1 = listStr.get(i);
            System.out.println(a1);
            String filename = snowflakeIdWorker.nextId() + "";
            //调用下载图片工具类,进行下载   循环下载图片
            DowloadUtil.dowloaImage(a1,filename,storePath);
        }

        return R.ok("文件下载成功！");
    }

package com.ruoyi.business.utils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;


public class DowloadUtil {

    
    public static void dowloaImage(String imageUrl, String formatName, String storePath) {
        InputStream is = null;
        FileOutputStream fos = null;
        File storeDir = new File(storePath);
        if (!storeDir.exists()) {
            storeDir.mkdirs();
        }
        String[] str = imageUrl.substring(imageUrl.lastIndexOf("/") + 1).split("\.");
        String suffix = null;
        if (str.length == 1) {
            suffix = "jpg";
        } else {
            suffix = str[1];
        }
        String filename = formatName + "." + suffix;

        try {
            URL url = new URL(imageUrl);
            URLConnection con = url.openConnection();
            is = con.getInputStream();
            fos = new FileOutputStream(new File(storeDir, filename));
            byte[] buff = new byte[1024];
            int len = 0;
            while ((len = is.read(buff)) != -1) {
                fos.write(buff, 0, len);
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (is != null) {
                    is.close();
                }
                if (fos != null) {
                    fos.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}