文件上传下载

单文件上传

<form action="/layui/upload" method="post" enctype="multipart/form-data">
    文件：<input type="file" name="file"/>
    <input type="submit"/>
</form>

 

  @postmapping(value = "upload")
    @responsebody
    public map upload(@requestparam("file") multipartfile file) {
        map map=new hashmap();
        try {
            if (file.isempty()) {
                map.put("msg","文件为空");
                return map;
            }
            // 获取文件名
            string filename = file.getoriginalfilename();
            log.info("上传的文件名为：" + filename);
            // 获取文件的后缀名
            string suffixname = filename.substring(filename.lastindexof("."));
            log.info("文件的后缀名为：" + suffixname);
            // 设置文件存储路径
            string filepath = "d:/测试文件上传下载功能/";
            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
            map.put("msg","上传成功");
            return map;
        }
        catch (illegalstateexception e) {
            e.printstacktrace();
        } catch (ioexception e) {
            e.printstacktrace();
        }
        map.put("msg","上传失败");
        return map;
    }

 

 多文件上传

<p>多文件上传</p>
<form method="post" enctype="multipart/form-data" action="/layui/batch">
    <p>文件1：<input type="file" name="file"/></p>
    <p>文件2：<input type="file" name="file"/></p>
    <p><input type="submit" value="上传"/></p>
</form>

 @postmapping("batch")
    @responsebody
    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:/测试文件上传下载功能/";
            if (!file.isempty()) {
                try {
                    byte[] bytes = file.getbytes();
                    stream = new bufferedoutputstream(new fileoutputstream(
                            new file(filepath + file.getoriginalfilename())));//设置文件路径及名字
                    stream.write(bytes);// 写入
                    stream.close();
                } catch (exception e) {
                    stream = null;
                    return "第 " + i + " 个文件上传失败 ==> "
                            + e.getmessage();
                }
            } else {
                return "第 " + i
                        + " 个文件上传失败因为文件为空";
            }
        }
        return "上传成功";
    }

 

文件下载

<p>文件下载</p>
<a href="/layui/download">下载文件</a>

 @getmapping("download")
    @responsebody
    public string downloadfile(httpservletrequest request, httpservletresponse response) {
        string filename = "交接内容.xlsx";// 文件名
        if (filename != null) {
            //设置文件路径
            file file = new file("c:/users/fanyx/desktop/交接内容.xlsx");
            //file file = new file(realpath , filename);
            if (file.exists()) {

                byte[] buffer = new byte[1024];
                fileinputstream fis = null;
                bufferedinputstream bis = null;
                try {
                    response.setcontenttype("application/force-download");// 设置强制下载不打开
                    response.addheader("content-disposition", "attachment;filename=" + new string(filename.getbytes("utf-8"),"iso8859-1"));// 设置文件名
                    fis = new fileinputstream(file);
                    bis = new bufferedinputstream(fis);
                    outputstream os = response.getoutputstream();
                    int i = bis.read(buffer);
                    while (i != -1) {
                        os.write(buffer, 0, i);
                        i = bis.read(buffer);
                    }
                    return "下载成功";
                } catch (exception e) {
                    e.printstacktrace();
                } finally {
                    if (bis != null) {
                        try {
                            bis.close();
                        } catch (ioexception e) {
                            e.printstacktrace();
                        }
                    }
                    if (fis != null) {
                        try {
                            fis.close();
                        } catch (ioexception e) {
                            e.printstacktrace();
                        }
                    }
                }
            }
        }
        return "下载失败";
    }