Java Springboot 根据图片链接生成图片下载链接 及 多个图片打包zip下载链接

Java Springboot 根据图片链接生成图片下载链接 及 多个图片打包zip下载链接

现有一些图片在服务器上的链接，在浏览器中打开这些链接是直接显示在浏览器页面的形式。

现在需要生成这些图片的单独下载以及打包下载链接，即在浏览器中打开下载链接后d出下载框提示下载。

由于前端存在跨域问题，所以图片下载由后台接口完成。

首先编写文件下载工具类：

 import java.net.URL;

 import java.net.MalformedURLException;

 import org.apache.commons.io.FileUtils;

 public class FileDownloadUtil {

 /**

      * 下载文件---返回下载后的文件存储路径

      *

      * @param url 文件路径

     * @param dir 目标存储目录

     * @param fileName 存储文件名

     * @return

     */

    public static void downloadHttpUrl(String url, String dir, String fileName) throws BusinessException {

        try {

        URL httpurl = new URL(url);

        File dirfile = new File(dir);

            if (!dirfile.exists()) {

                dirfile.mkdirs();

            }

            FileUtils.copyURLToFile(httpurl, new File(dir+fileName));

        } catch (MalformedURLException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();26         }

    }

     public static boolean deleteFile(File file) {

         if (file.exists()) {

             return file.delete();

         }

         return false;

     }

 ｝

单张图片下载

Controller层接口：

 import org.apache.commons.lang.StringUtils;

 import java.io.*;

 protected HttpServletResponse response;

 /**

      * 单张图片下载

      *

      * @param url 要下载的图片url

      * @author: nemowang

      */

     @ApiImplicitParams({

             @ApiImplicitParam(name = "url", value = "图片url", required = true, dataType = "String", paramType = "query"),

     })

     @ApiOperation(value = "单张图片下载", notes = "单张图片下载")

     @RequestMapping(value = "/downloadPicture", method = RequestMethod.GET)

     public void downloadPicture(String url) {

         // 拼接完整图片路径。

这里填写图片链接

         String urlPath = "";

         // 获取图片文件后缀名

         String postfix = "." + StringUtils.substringAfterLast(url, ".");

         // 获取当前类的所在项目路径

         File directory = new File("");

         String courseFile;

         String srcPath;

         File srcFile = null;

         FileInputStream fileInputStream = null;

         InputStream fis = null;

         OutputStream out = null;

         try {

             courseFile = directory.getCanonicalPath();

             String fileName = "\\" + StringUtil.getUUID() + postfix;

             // 下载文件

             FileDownloadUtil.downloadHttpUrl(urlPath, courseFile, fileName);

             srcPath = courseFile + fileName;

             srcFile = new File(srcPath);

             fileInputStream = new FileInputStream(srcPath);

             fis = new BufferedInputStream(fileInputStream);

             byte[] buffer = new byte[fis.available()];

             fis.read(buffer);

             response.setContentType("application/octet-stream");

             response.setHeader("Content-disposition", "attachment;filename=" + fileName);

             out = response.getOutputStream();

             out.write(buffer);

             out.flush();

             out.close();

         } catch (Exception e) {

             e.printStackTrace();

         } finally {

             try {

                 if (fileInputStream != null) {

                     fileInputStream.close();

                 }

                 if (fis != null) {

                     fis.close();

                 }

                 if (out != null) {

                     out.close();

                 }

             } catch (IOException e) {

                 e.printStackTrace();

             }

         }

         // 删除中间文件

         if (srcFile != null) {

             System.out.println(FileDownloadUtil.deleteFile(srcFile));

         }

     }

因为是GET请求，所以直接拼接接口路由+参数，用浏览器打开就能d出下载。

至此单张图片下载接口结束。

多张图片打包下载

Controller层接口：

 /**

      * 图片打包下载

      */

     @ApiImplicitParams({

             @ApiImplicitParam(name = "urls", value = "图片url列表", required = true, dataType = "List", paramType = "query"),

     })

     @ApiOperation(value = "图片打包下载", notes = "图片打包下载")

     @RequestMapping(value = "/downloadPictureList", method = RequestMethod.GET)

     public void downloadPictureList(List urls) {

         List<String> fileNameList = new ArrayList<>();

         for (int i = 0; i < urls.size(); i++) {

             // 获取文件名

             fileNameList.add(StringUtils.substringAfterLast(urls.get(i), "/"));

             // 拼接完整图片路径

             urls.set(i, DOMAIN + urls.get(i));

         }

         // 获取当前类的所在项目路径

         File directory = new File("");

         String courseFile;

         String srcPath;

         File srcFile = null;

         // 要打包的文件列表

         List<File> fileList = new ArrayList<>();

         ZipOutputStream zos = null;

         OutputStream out = null;

         try {

             courseFile = directory.getCanonicalPath();

             // 下载文件

             for (int i = 0; i < urls.size(); i++) {

                 String fileName = "\\" + fileNameList.get(i);

                 FileDownloadUtil.downloadHttpUrl(urls.get(i), courseFile, fileName);

                 srcPath = courseFile + fileName;

                 srcFile = new File(srcPath);

                 fileList.add(srcFile);

             }

             long start = System.currentTimeMillis();

             response.setContentType("application/x-zip-compressed");

             response.setHeader("Content-disposition", "attachment;filename=" + StringUtil.getUUID() + ".zip");

             out = response.getOutputStream();

             zos = new ZipOutputStream(out);

             for (File file : fileList) {

                 byte[] buf = new byte[BUFFER_SIZE];

                 zos.putNextEntry(new ZipEntry(file.getName()));

                 int len;

                 FileInputStream in = new FileInputStream(file);

                 while ((len = in.read(buf)) != -1) {

                     zos.write(buf, 0, len);

                 }

                 zos.closeEntry();

                 in.close();

             }

             long end = System.currentTimeMillis();

             System.out.println("压缩完成，耗时：" + (end - start) + " ms");

             out.flush();

         } catch (IOException e) {

             e.printStackTrace();

         } catch (Exception e) {

                 throw new RuntimeException("zip error from ZipUtils", e);

         } finally {

             if (zos != null) {

                 try {

                     zos.close();

                 } catch (IOException e) {

                     e.printStackTrace();

                 }

             }

             if (out != null) {

                 try {

                     zos.close();

                 } catch (IOException e) {

                     e.printStackTrace();

                 }

             }

         }

         // 删除中间文件

         if (fileList != null) {

             for (File file : fileList) {

                 System.out.println(FileDownloadUtil.deleteFile(file));

             }

         }

     }

同样是GET请求，所以也是拼接接口路由+参数，用浏览器打开就能d出下载。