从网络获取多张二维码图片，压缩打包下载

项目最近有这个小需求，记录一下。

controller层：

 1 /**
 2      * 批量下载二维码图片
 3      *
 4      * @param deviceIdStr
 5      */
 6     @RequestMapping("qr_code")
 7     public void batchDownLoadQrCode(String deviceIdStr, HttpServletResponse response) throws Exception {
 8         String[] deviceId = deviceIdStr.split(",");
 9         List<Integer> deviceIds = new ArrayList<>();
10         for (String id : deviceId) {
11             deviceIds.add(Integer.valueOf(id));
12         }
13         DeviceQueryForm deviceQueryForm = new DeviceQueryForm();
14         deviceQueryForm.setDeviceIds(deviceIds);
15         List<Device> deviceList = deviceClient.getDeviceList(deviceQueryForm);
16 
17 //      生成zip文件
18         String name = "qrCode" + System.currentTimeMillis();
19         String zipFileName = name + ".zip";
20         String projectPath = System.getProperty("user.dir");
21         String path = projectPath + File.separator + "qrCode";
22         
23         File file = new File(path);
24         //文件夹不存在则创建
25         if (!file.exists()) {
26             file.mkdirs();
27         }
28         //新建一个zip
29         File zipFile = new File(path + File.separator + zipFileName);
30         ZipOutputStream zipOutputStream = new ZipOutputStream(new FileOutputStream(zipFile));
31 
32         for (Device device : deviceList) {
33             String imageName = device.getDeviceCode() + ".jpg";
34 
35             if (StringUtils.isBlank(device.getQrCodeUrl())) {
36                 continue;
37             }
38 
39             URL url = new URL(device.getQrCodeUrl());
40             URLConnection conn = url.openConnection();
41             conn.setConnectTimeout(3000);
42             InputStream inputStream = conn.getInputStream();
43             File imageFile = FileUtil.generateImageFile(inputStream, path, imageName);
44 
45             FileUtil.generateZip(zipOutputStream, imageFile);
46 
47             //删除图片
48             if (imageFile.exists()) {
49                 imageFile.delete();
50             }
51         }
52 
53         zipOutputStream.flush();
54         zipOutputStream.close();
55 
56         //输出到客户端
57         OutputStream out = response.getOutputStream();
58         response.reset();
59         response.setHeader("Content-Disposition", "attachment;filename=" + zipFileName);
60         response.setContentType("application/zip;charset=utf-8");
61         response.setCharacterEncoding("UTF-8");
62         out.write(FileUtils.readFileToByteArray(zipFile));
63         out.flush();
64         out.close();
65         //删除压缩包
66         if (zipFile.exists()) {
67             zipFile.delete();
68         }
69     }

工具类：

 1 package cn.ubox.mbss.ops.backend.utils;
 2 
 3 import java.io.*;
 4 import java.util.zip.ZipEntry;
 5 import java.util.zip.ZipOutputStream;
 6 
 7 /**
 8  * @Author: 2YSP
 9  * @Description:
10  * @Date: Created in 2017/12/13
11  */
12 public class FileUtil {
13     /**
14      * 生成二维码图片
15      * @param inputStream
16      * @param path
17      * @param imageName
18      */
19     public static File generateImageFile(InputStream inputStream,String path,String imageName){
20         FileOutputStream outStream = null;
21         File imageFile = null;
22         BufferedInputStream bufferStream = null;
23         try{
24             //创建二维码图片
25             imageFile = new File(path + File.separator + imageName);
26 
27             outStream = new FileOutputStream(imageFile);
28             bufferStream = new BufferedInputStream(inputStream);
29             byte[] data = new byte[1024 * 100];
30             int len = 0;
31             while ((len = bufferStream.read(data)) != -1) {
32                 //写入数据
33                 outStream.write(data, 0, len);
34             }
35         }catch (IOException e){
36             e.printStackTrace();
37         }finally {
38             if (outStream != null){
39                 try {
40                     outStream.flush();
41                     outStream.close();
42                 } catch (IOException e) {
43                     e.printStackTrace();
44                 }
45             }
46             if (bufferStream != null){
47                 try {
48                     bufferStream.close();
49                 } catch (IOException e) {
50                     e.printStackTrace();
51                 }
52             }
53         }
54         return imageFile;
55     }
56 
57     /**
58      * 压缩图片为zip格式
59      * @param zipOutputStream
60      * @param imageFile
61      *
62      */
63     public static void generateZip(ZipOutputStream zipOutputStream,File imageFile){
64         BufferedInputStream bufferStream = null;
65         try {
66             InputStream input = new FileInputStream(imageFile);
67             String zipEntryName = imageFile.getName();
68             byte[] bytes = new byte[1024 * 100];// 读写缓冲区
69             bufferStream =  new BufferedInputStream(input);// 输入缓冲流
70 
71             ZipEntry zipEntry = new ZipEntry(zipEntryName);
72             // 定位到该压缩条目位置，开始写入文件到压缩包中
73             zipOutputStream.putNextEntry(zipEntry);
74             int len = 0;
75             while ((len = bufferStream.read(bytes)) != -1) {
76                 zipOutputStream.write(bytes, 0, len);
77             }
78         }catch (IOException e){
79             e.printStackTrace();
80         }finally {
81             if (bufferStream != null){
82                 try {
83                     bufferStream.close();
84                 } catch (IOException e) {
85                     e.printStackTrace();
86                 }
87             }
88         }
89     }
90 }

如果大家觉得有需要优化的地方，欢迎留言讨论。