• springBoot实现文件上传与下载


    1. 文件下载

    准备一个文件C:/Users/admin/Desktop/test.xlsx

     /**
         * 定制分析下载模板文档
         * @param response
         * @return
         */
        @RequestMapping("/downLoadTemplateExcel")
        public Info downLoadTemplateExcel(HttpServletResponse response){
            logger.info("/customAnalysisConfig/downLoadTemplateExcel");
            Info infos=new Info();
            // 创建输入输出流
            BufferedInputStream bis = null;
            BufferedOutputStream bos = null;
            //String url = "C:/Users/admin/Desktop/test.xlsx";
            String url =null;
            if(environment.equals("local")){//本地文件路径
                url ="C:/Users/admin/Desktop/test.xlsx";
            }else {//服务器文件路径
                url = "/usr/java/test.xlsx";
            }
            String downLoadPath = url;
            String fileName="template.xlsx";//生成的文件名
            File file2 = new File(downLoadPath);//要下载的文件对象
            if (!file2.exists()) {//如果目录不存在,创建目录
                file2.mkdirs();
            }
            long fileLength = file2.length();// 获取文件长度
            try {
                //Content-Disposition: attachment; filename="filename.xls"
                //第一个参数是attachment(意味着消息体应该被下载到本地;大多数浏览器会呈现一个“保存为”的对话框,
                // 将filename的值预填为下载后的文件名,假如它存在的话)
                response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes("utf-8"), "ISO8859-1"));
                //Content-Type 实体头部用于指示资源的MIME类型 media type
                response.setHeader("Content-Type", "application/json");
                //Content-Length, HTTP消息长度, 用十进制数字表示的八位字节的数目
                response.setHeader("Content-Length", String.valueOf(fileLength));
                // 创建输入输出流实例
                bis = new BufferedInputStream(new FileInputStream(downLoadPath));
                bos = new BufferedOutputStream(response.getOutputStream());
                // 创建字节缓冲大小
                byte[] buff = new byte[2048];
                int bytesRead;
                while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
                    bos.write(buff, 0, bytesRead);
                }
            }catch (Exception e){
                e.printStackTrace();
            }finally {
                if (bis != null)
                    try {
                        bis.close();// 关闭输入流
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                if (bos != null)
                    try {
                        bos.close();// 关闭输出流
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
            }
            infos.setCode("1");
            infos.setMsg("成功");
            return infos ;
        }

    2. 单文件上传

    准备一个upload.html

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
        <form action="http://localhost:4000/pdClientManagerSystem/customAnalysisConfig/upload" method="post" enctype="multipart/form-data">
            <input type="file" name="file" value="Select your file: ">
            <input type="submit" value="Upload">
        </form>
    </body>
    </html>

    注意这里的 name="file"

    //单文件上传的功能
        @RequestMapping(value = "/upload")
        public String upload(MultipartFile file) {
            try {
                if (file.isEmpty()) {
                    return "file is empty";
                }
                String fileName = file.getOriginalFilename();//获取文件名
                String suffixName = fileName.substring(fileName.lastIndexOf("."));//切割文件名
                log.info("上传的文件名为:" + fileName + " 后缀名为" + suffixName);
                // 设置文件存储路径(D盘),你可以存放在你想要指定的路径里面。
                String filePath = "D:/upload";
                //文件存放路径=filePath+/+ fileName
                String path = filePath + "/" + fileName;
                File dest = new File(path);
                // 检测是否存在目录
                if (!dest.getParentFile().exists()) {
                    dest.getParentFile().mkdirs();// 新建文件夹
                }
                file.transferTo(dest);// 文件写入到上述的存放路径path
                return "upload success";
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "upload failure";
        }

    3. 多文件上传

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>批量文件上传</title>
    </head>
    <body>
    <form method="post" action="/batch" enctype="multipart/form-data">
    <input type="file" name="file"><br> <input type="file" name="file"><br> <input type="file" name="file"><br> <br> <input type="submit" value="提交"> </form> </body> </html>

    java代码

    //多文件上传的功能
        @RequestMapping("/batch")
        public String handleFileUpload(HttpServletRequest request) {
            List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");
            MultipartFile file = null;
            BufferedOutputStream stream = null;
            for (int i = 0; i < files.size(); ++i) {
                file = files.get(i);
                String filePath = "D:/uploads";
                if (!file.isEmpty()) {
                    try {
                        byte[] bytes = file.getBytes();
                        stream = new BufferedOutputStream(new FileOutputStream(
                                new File(filePath  + "/" + file.getOriginalFilename())));
                        stream.write(bytes);// 写入
                        stream.close();
                    } catch (Exception e) {
                        stream = null;
                        return "the " + i + " file upload failure";
                    }
                } else {
                    return "the " + i + " file is empty";
                }
            }
            return "upload Multifile success";
        }
    /**
    * 定制分析下载模板文档
    * @param response
    * @return
    */
    @RequestMapping("/downLoadTemplateExcel")
    public Info downLoadTemplateExcel(HttpServletResponse response){
    logger.info("/customAnalysisConfig/downLoadTemplateExcel");
    Info infos=new Info();
    // 创建输入输出流
    BufferedInputStream bis = null;
    BufferedOutputStream bos = null;
    //String url = "C:/Users/admin/Desktop/test.xlsx";
    String url =null;
    if(environment.equals("local")){//本地文件路径
    url ="C:/Users/admin/Desktop/test.xlsx";
    }else {//服务器文件路径
    url = "/usr/java/test.xlsx";
    }
    String downLoadPath = url;
    String fileName="template.xlsx";//生成的文件名
    File file2 = new File(downLoadPath);//要下载的文件对象
    if (!file2.exists()) {//如果目录不存在,创建目录
    file2.mkdirs();
    }
    long fileLength = file2.length();// 获取文件长度
    try {
    //Content-Disposition: attachment; filename="filename.xls"
    //第一个参数是attachment(意味着消息体应该被下载到本地;大多数浏览器会呈现一个保存为的对话框,
    // filename的值预填为下载后的文件名,假如它存在的话)
    response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes("utf-8"), "ISO8859-1"));
    //Content-Type 实体头部用于指示资源的MIME类型 media type
    response.setHeader("Content-Type", "application/json");
    //Content-Length, HTTP消息长度, 用十进制数字表示的八位字节的数目
    response.setHeader("Content-Length", String.valueOf(fileLength));
    // 创建输入输出流实例
    bis = new BufferedInputStream(new FileInputStream(downLoadPath));
    bos = new BufferedOutputStream(response.getOutputStream());
    // 创建字节缓冲大小
    byte[] buff = new byte[2048];
    int bytesRead;
    while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
    bos.write(buff, 0, bytesRead);
    }
    }catch (Exception e){
    e.printStackTrace();
    }finally {
    if (bis != null)
    try {
    bis.close();// 关闭输入流
    } catch (IOException e) {
    e.printStackTrace();
    }
    if (bos != null)
    try {
    bos.close();// 关闭输出流
    } catch (IOException e) {
    e.printStackTrace();
    }
    }
    infos.setCode("1");
    infos.setMsg("成功");
    return infos ;
    }
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  • 原文地址:https://www.cnblogs.com/lusaisai/p/13329729.html
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