前端上传和下载

Java前后端的上传和下载

上传

前端代码

"使用了bootstrap样式"
<label class="input-group-btn">
    <span class="btn btn-success">
        <i class="fas fa-file-upload"></i>
        导入数据<input id="myFile" type="file" name="file" style="display: none;">
    </span>
</label>

"Jquery代码上传"

$("#myFile").on('change',function () {
    "创建formData"
    var formData = new FormData();
    "获取文件数据"
    var file = $("#myFile")[0].files[0];
    formData.append("files",file);
    $.ajax({
        type: "POST",
        url: "<%=request.getContextPath()%>/jtxyh/uploadFile",
        dataType : "json",
        mimeType:"multipart/form-data",
        processData: false,  "注意：让jQuery不要处理数据"
        contentType: false,  "注意：让jQuery不要设置contentType"
        data: formData,
        success:function (data) {
            "这里写上传后操作"
        }
    })
});

后端代码

@PostMapping("/uploadFile")
@ResponseBody
                                "这里这个必须这样写"
public List<String> uploadFile(@RequestParam(value = "files", required = false) MultipartFile multipartFile) {
    "存储已经存在的数据"
    List<String> alreadyData = new ArrayList<>();
    "存入数据库的数据"
    List<CommBrand> newData = new ArrayList<>();
    if (multipartFile != null) {
        InputStream inputStream = null;
        try {
            inputStream = multipartFile.getInputStream();
        } catch (Exception e) {
            e.printStackTrace();
        }
        "调用读取Excel的工具类"
        List<CommBrand> commBrands = ReadCommBrandExcelUtil.readExcel(inputStream);
        "判断数据是否重复"
        for (int i = 0; i < commBrands.size(); i++) {
            "查询这条数据是否存在数据库中"
            int count = commBrandService.selectByBrandNameReInt(commBrands.get(i).getBrandName());
            "如果大于0代表数据库中已经有这个数据了"
            if (count > 0) {
                alreadyData.add(commBrands.get(i).getBrandName());
            } else {
                newData.add(commBrands.get(i));
            }
        }
        if (newData.size() != 0) {
            "批量添加数据"
            insertBulkCommBrand(newData);
        }
    }
    return alreadyData;
}

下载

前端代码

1
2
3

<button id="downloadBtn" type="button" class="btn btn-success btn-block">
    <i class="fas fa-download"></i> <span>下载</span>
</button>

1	`window.location.href = '<%=request.getContextPath()%>/deliverInfo/download?拼上需要上传的数据;'`

后端代码

@GetMapping("/download")
public void downloadDeliverInfo(String deliverIdArray, HttpServletResponse response){
"调用工具类下载"
try {
    "设置响应流"
    response.setHeader("content-disposition", "attoachment;fileName="+URLEncoder.encode(new SimpleDateFormat("yyyy年MM月dd日HH时mm分ss秒").format(new Date()),"UTF-8") +".docx");
    OutputStream outputStream = response.getOutputStream();
    word.write(deliverIdArray,outputStream);
    byte buffer[] = new byte[1024];
    outputStream.flush();
    outputStream.close();
} catch (Exception e) {
    e.printStackTrace();
}
}