文件上傳格式,後臺接收處理

前端上傳文件

1. file格式 創建formData來完成file上傳

<input type="file" id="imgfile" name="pic" multiple>
<script>
    $("#imgfile").change(function () {
        var formData = new FormData();
        $.each($('#imgfile')[0].files, function (i, file) {
            formData.set('upload_file'+ i, file);
        });
        //processData: false, contentType: false,多用來處理異步上傳二進制文件。
        $.ajax({
            url: 'xxx',
            type: 'POST',
            data: formData,                    // 上傳formdata封裝的數據
            dataType: 'JSON',
            cache: false,                      // 不緩存
            processData: false,                // jQuery不要去處理髮送的數據
            contentType: false,                // jQuery不要去設置Content-Type請求頭
            success:function (data) {           //成功回調
                console.log(data);
            }
        });
    });
 </script>

2. base64格式
   將多個base64圖片直接放在數組中,JSON.stringfy();以數組的字符串格式傳給後臺
3. Blob流格式
   創建formData來完成Blob流上傳

管理後臺

**MultipartFile接收**

MultipartFile可以接收前端file類型和blob類型的文件

SpringMVC提供的org.springframework.web.multipart.MultipartFile很強大，接收file只需要@RequestParam(value = “img”) MultipartFile file就可以了，

@Controller
@RequestMapping("/user")
public class UserController extends BaseController {
    private static Logger logger = LoggerFactory.getLogger(UserController.class);
    @Value(value = "${image.path:./img}")
    private String imagePath;

    @Value(value = "${image.host:http://localhost}")
    private String imageHost;

    @RequestMapping(value = "/upload/file", method = RequestMethod.POST)
    @ResponseBody
    public Result<String> saveFile(@RequestParam(value = "img") MultipartFile file) {
        StringBuffer fileName = new StringBuffer();
        fileName.append(UUID.randomUUID().toString().replaceAll("-", ""));
        String type = file.getContentType();
        if ("image/png".equals(type)) {
            fileName.append(".png");
        } else if ("image/jpeg".equals(type)) {
            fileName.append(".jpeg");
        } else if ("image/gif".equals(type)) {
            fileName.append(".gif");
        } else {
            return new Result.Builder<String>()
                    .code(-1)
                    .msg("請選擇.png.jpg格式的圖片")
                    .build();
        }
        if (file.getSize() > 1024000L) {
            return new Result.Builder<String>()
                    .code(-1)
                    .msg("圖片超過1Mb")
                    .build();
        }
        try {
            file.transferTo(new File(imagePath, fileName.toString()));
            return new Result.Builder<String>()
                    .code(0)
                    .msg("成功")
                    .data(imageHost + fileName.toString())
                    .build();
        } catch (IOException e) {
            e.printStackTrace();
            return new Result.Builder<String>()
                    .code(-1)
                    .msg("保存失敗")
                    .build();
        }
    }
}

Base64字符串接收

    @RequestMapping(value = "/upload/base64", method = RequestMethod.POST)
    @ResponseBody
    public Result<String> saveBase64(@RequestParam(value = "img") String base64Str) {
        StringBuffer fileName = new StringBuffer();
        fileName.append(UUID.randomUUID().toString().replaceAll("-", ""));
        if (StringUtils.isBlank(base64Str)) {
            return new Result.Builder<String>()
                    .code(-1)
                    .msg("file不可缺省")
                    .build();
        } else if (base64Str.indexOf("data:image/png;") != -1) {
            base64Str = base64Str.replace("data:image/png;base64,", "");
            fileName.append(".png");
        } else if (base64Str.indexOf("data:image/jpeg;") != -1) {
            base64Str = base64Str.replace("data:image/jpeg;base64,", "");
            fileName.append(".jpeg");
        } else {
            return new Result.Builder<String>()
                    .code(-1)
                    .msg("請選擇.png.jpg格式的圖片")
                    .build();
        }
        File file = new File(imagePath, fileName.toString());
        byte[] fileBytes = Base64.getDecoder().decode(base64Str);
        try {
            FileUtils.writeByteArrayToFile(file, fileBytes);
        } catch (IOException e) {
            e.printStackTrace();
            return new Result.Builder<String>()
                    .code(-1)
                    .msg("保存失敗")
                    .build();
        }
        return new Result.Builder<String>()
                .code(0)
                .msg("成功")
                .data(imageHost + fileName.toString())
                .build();
    }

參考:
https://blog.csdn.net/qq_34664239/article/details/94595508
https://blog.csdn.net/yimcarson/article/details/84937674