批量下载网络图片并zip打包

Posted 2020-09-16 zjn漾子

该功能分为三步：

先把图片下载到本地的一个文件夹

public  void download(String urlString, String filename,String savePath) throws Exception {
    // 构造URL
    URL url = new URL(urlString);
    // 打开连接
    URLConnection con = url.openConnection();
    //设置请求超时为5s
    con.setConnectTimeout(5 * 1000);
    // 输入流
    InputStream is = con.getInputStream();

    // 1K的数据缓冲
    byte[] bs = new byte[1024];
    // 读取到的数据长度
    int len;
    // 输出的文件流
    File sf=new File(savePath);
    if(!sf.exists()){
        sf.mkdirs();
    }
    OutputStream os = new FileOutputStream(sf.getPath()+"\\"+filename);
    // 开始读取
    while ((len = is.read(bs)) != -1) {
        os.write(bs, 0, len);
    }
    // 完毕，关闭所有链接
    os.close();
    is.close();
}

打包为zip

@RequestMapping(value = "/downZip")
    public void downZip(String tcLwIds,HttpServletResponse response) throws Exception {
        List<File> files = new ArrayList<File>();
        List<String>pathDb=new ArrayList<>();
        pathDb.add("group1/M00/00/73/wKgCCFkC56OAbvweAABrRuCppJE685.png");
        pathDb.add("group1/M00/00/73/wKgCCFkC56OAYwToAAAuJ6ZQ3Lc233.png");
        pathDb.add("group1/M00/00/73/wKgCCFkC56OAQTGpAAAm_2X7-GM329.png");
        pathDb.add("group1/M00/00/5D/wKgCD1kC6FCAZxwSAAAm_2X7-GM372.png");
        for(int m=0;m<pathDb.size();m++){
            String filePath=STORAGE_SERVER_URL+pathDb.get(m);
            String fileName=pathDb.get(m).split("/")[4];
            String path=test5.class.getResource("/").getFile();
            download(filePath, fileName,path);
            File file = new File(path+fileName);
            files.add(file);
        }

        String fileName = UUID.randomUUID().toString() + ".zip";
        //在服务器端创建打包下载的临时文件
        String outFilePath =  test5.class.getResource("/").getFile();
        createFile(outFilePath,fileName);
        File file = new File(outFilePath+fileName);
        //文件输出流
        FileOutputStream outStream = new FileOutputStream(file);
        //压缩流
        ZipOutputStream toClient = new ZipOutputStream(outStream);
        // toClient.setEncoding("gbk");
        zipFile(files, toClient);
        toClient.close();
        outStream.close();
        this.downloadFile(file, response, true);
//删除本地文件
        for(File path:files) {
            path.delete();
        }
    }

    //创建文件
    public void createFile(String path,String fileName){
        //path表示你所创建文件的路径
        File f = new File(path);
        // fileName表示你创建的文件名；为txt类型；
        File file = new File(f,fileName);
        if(!file.exists()){
            try {
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }


    }
    /** 压缩文件列表中的文件
     * @param files
     * @param outputStream
     * @throws IOException
     */
    public static void zipFile(List<File> files, ZipOutputStream outputStream) throws IOException,ServletException
    {
        try {
            int size = files.size();
// 压缩列表中的文件
            for (int i = 0; i < size; i++) {
                File file =files.get(i);
                zipFile(file, outputStream);
            }
        } catch (IOException e) {
            throw e;
        }
    }
    /** 将文件写入到zip文件中
     *
     * @param inputFile
     * @param outputstream
     * @throws Exception
     */
    public static void zipFile(File inputFile, ZipOutputStream outputstream) throws IOException,ServletException
    {
        try {
            if (inputFile.exists()) {
                if (inputFile.isFile()) {
                    FileInputStream inStream = new FileInputStream(inputFile);
                    BufferedInputStream bInStream = new BufferedInputStream(
                            inStream);
                    ZipEntry entry = new ZipEntry(inputFile.getName());
                    outputstream.putNextEntry(entry);


                    final int MAX_BYTE = 10 * 1024 * 1024; // 最大的流为10M
                    long streamTotal = 0; // 接受流的容量
                    int streamNum = 0; // 流需要分开的数量
                    int leaveByte = 0; // 文件剩下的字符数
                    byte[] inOutbyte; // byte数组接受文件的数据


                    streamTotal = bInStream.available(); // 通过available方法取得流的最大字符数
                    streamNum = (int) Math.floor(streamTotal / MAX_BYTE); // 取得流文件需要分开的数量
                    leaveByte = (int) streamTotal % MAX_BYTE; // 分开文件之后,剩余的数量


                    if (streamNum > 0) {
                        for (int j = 0; j < streamNum; ++j) {
                            inOutbyte = new byte[MAX_BYTE];
                            // 读入流,保存在byte数组
                            bInStream.read(inOutbyte, 0, MAX_BYTE);
                            outputstream.write(inOutbyte, 0, MAX_BYTE); // 写出流
                        }
                    }
                    // 写出剩下的流数据
                    inOutbyte = new byte[leaveByte];
                    bInStream.read(inOutbyte, 0, leaveByte);
                    outputstream.write(inOutbyte);
                    outputstream.closeEntry(); // Closes the current ZIP entry
                    // and positions the stream for
                    // writing the next entry
                    bInStream.close(); // 关闭
                    inStream.close();
                }
            } else {
                throw new ServletException("文件不存在！");
            }
        } catch (IOException e) {
            throw e;
        }
    }


删除存在本地的文件

for(File path:files) {
            path.delete();
        }

参考：http://takeme.iteye.com/blog/1683380
http://bbs.csdn.net/topics/340174173
http://www.aiisen.com/java-batch-download-photos-zh.html