文件上传-下载

末蓝、 2022-04-02 11:58 310阅读 0赞

上传原理与图片上传类似  详见 维权资料上传下载   
    一、上传
    <input class="upload" type="file" style="display: none"
           οnchange="uploadDatum(this)"/>

// 上传资料
    $(function () {
        $(".upload_a").on("click", function () {
            $(".upload").click();           // 触发文件选择框
        })
    })
    function uploadDatum(fileThis){
        if(!wdbUserLonged){
            UserLoginObj.loginShow();
            return;
        }
        var fileObj = $(fileThis)[0].files[0];
        if (typeof (fileObj) == "undefined" || fileObj.size <= 0) {
            return;
        }
        var pno = $("#bcpno").val();
        var pname = $("#bcpname").val();
        var pid = $("#pid").val();
        // FormData可以凭空创建一个对象，然后往这个对象里面添加数据，然后直接作为data传递到后台，不需要写一行html代码
        // 这里需要传给Controller-@RequestParam("upfile") MultipartFile multipartFile对应的fileObj文件对象，以及其它参数
        // 故可以使用formData方式传递参数到后台
        var formData = new FormData();
        formData.append("upfile", fileObj); // 文件对象 它的名称upfile要与controller中@RequestParam("upfile") MultipartFile multipartFile对应
        formData.append("pno",pno);
        formData.append("pname",pname);
        var action = basePath+"/user/safeguardingRightsDatum/uploadDatum";
        $.ajax({
            url: action,
            data: formData,
            type: "Post",
            cache: false,//上传文件无需缓存
            processData: false, 告诉jQuery不要去处理发送的数据
            contentType: false, //告诉jQuery不要去设置Content-Type请求头
            success: function (data) {
                if(data.code == "88"){
                    successPopup(data.message);
                    location.reload();
                }else{
                    failPopup(data.message);
                }
            }
        })
    }

@RequestMapping("/uploadDatum")
    @ResponseBody
    public ProcessBack uploadImage(@RequestParam("upfile") MultipartFile multipartFile, SafeguardingRightsDatum datument){
        PreCommonMember preCommonMember =  getPreCommonMemberByPC();
        ProcessBack processBack = datumService.uploadFile(multipartFile,request);
        return processBack;
    }

public ProcessBack uploadFile(MultipartFile multipartFile,HttpServletRequest request) {
        ProcessBack processBack = new ProcessBack();
        try{
            Map<String,String> uploadMap = fastDFSUploadComponent.uploadDatumentFile(multipartFile);
            if(uploadMap.get(FastDFSUploadComponent.FDFS_STATE).equals(FastDFSUploadComponent.FDFS_FAIL_STATUS)){//图片上传失败
                throw new IllegalArgumentException("资料上传失败");
            }
            String url = (String) uploadMap.get(FastDFSUploadComponent.FDFS_URL);  // 服务器上的文件路径
            String completeName = (String) uploadMap.get(FastDFSUploadComponent.FDFS_TITLE);  //文件全名
            String pno = request.getParameter("pno");
            String pname = request.getParameter("pname");
            PreCommonMember preCommonMember = (PreCommonMember) request.getSession().getAttribute(Session_Constant.USER);
            // String input="7421847.12940219.124214.exe";
            // String中的lastIndexOf方法，是获取要搜索的字符、字符串最后次出现的位置  xx.substring(n)表示去掉前n个字符，返回剩下的字符串
            String houzhui = completeName.substring(completeName.lastIndexOf(".")+1);  // 获取最后一个.的位置，然后截取它之后的字符串
            System.out.println("后缀名为:"+houzhui);    // exe
            int i = completeName.lastIndexOf(houzhui);
            String qianzhui = completeName.substring(0,i-1);
            System.out.println("文件名为:"+qianzhui);
            SafeguardingRightsDatum datum = new SafeguardingRightsDatum();
            datum.setPno(pno);
            datum.setPname(pname);
            datum.setUid(preCommonMember.getUid());
            datum.setUsername(preCommonMember.getUsername());
            datum.setForm(houzhui);
            datum.setDatumname(qianzhui);
            datum.setDatumurl(url);
            datum.setUploadtime(System.currentTimeMillis());
            datumMapper.insert(datum);
            datum.setUploadTimeStr(DateUtils.formatYY_MM_DD(datum.getUploadtime()));
            datum.setDatumurl(this.fdfsurl + datum.getDatumurl());
            processBack.setData(datum);  // 返回给页面显示
            processBack.setCode(ProcessBack.SUCCESS_CODE);
            processBack.setMessage("资料上传成功");
            return processBack;
        }catch(RuntimeException e){
            e.printStackTrace();
            TransactionAspectSupport.currentTransactionStatus().setRollbackOnly();  //数据回滚
        }catch(Exception e){
            e.printStackTrace();
        }
        processBack.setCode(ProcessBack.FAIL_CODE);
        processBack.setMessage(ProcessBack.EXCEPTION_MESSAGE);
        return processBack;
    }

二、下载：a标签 href="文件访问路径"  download="文件前缀.文件后缀(格式)">