react+spring boot上载文件和表单数据

Question

我有一个案例像在我的表格（前端），我可以填写个人数据（姓名，地址，DOB）然后我可以附上多个图像。

在我的spring boot控制器中：

@RequestMapping(value = "/addCustOrder", method = RequestMethod.POST, consumes = {"multipart/form-data"})
    public String CustomerOrder(@ModelAttribute CustOrderRequest coReq, HttpServletRequest request) {
    System.out.println("debug ************** ");
    System.out.println("ReceiverName :: " + coReq.getReceiverName());
    System.out.println("attachmentFile :: " + coReq.getFileAttachment().length);
}

我的模型包装：

public class CustOrderRequest {
    private String receiverName;
    private String receiverPhone;
    private String itemDescription;
    private MultipartFile[] fileAttachment;
}
//setter & getter 

const payload = JSON.stringify({
    id: values.id,
    receiverName: values.receiverName,
    receiverPhone: values.receiverPhone,
    itemDescription: values.itemDescription,
    fileAttachment: values.fileAttachment
});

axios.post(urlApi, payload)
    .then(r => {
    // success request 
    });

更新的前端代码：

let fd = new FormData();
fd.append("fileAttachment", values.fileAttachment);
fd.append("receiverName", values.receiverName);

axios.post(urlApi, fd)
    .then(r => {
    // success request 
    });

使用formdata更改了前端代码，然后在后端出现错误：

2020-02-07T17:36:10.231+0700 WARN Resolved [org.springframework.validation.BindException: org.springframework.validation.BeanPropertyBindingResult: 1 errors
Field error in object 'custOrderRequest' on field 'fileAttachment': rejected value [[object FileList]]; codes [typeMismatch.custOrderRequest.fileAttachment,typeMismatch.fileAttachment,typeMismatch.[Lorg.springframework.web.multipart.MultipartFile;,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [custOrderRequest.fileAttachment,fileAttachment]; arguments []; default message [fileAttachment]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile[]' for property 'fileAttachment'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile' for property 'fileAttachment[0]': no matching editors or conversion strategy found]]

Answer 1

您正在服务器端使用multipart/form-data，因此必须将数据作为formdata发送。

使用const formData=new formData（form）；而不是json.stringify

您的第二个例外是绑定错误，您试图将string绑定到multipart，这是因为这一行

fd.append("fileAttachment", values.fileAttachment);

1-您可以在文件的表单中设置OnChange，如OnFileChangeHandler

<input type="file" className="form-control" name="file" onChange={this.onFileChangeHandler}/>

2-在formdata中设置上载文件并发送（如下面的代码）

onchange的正文可以如下所示

onFileChangeHandler = (e) => {
        e.preventDefault();
        this.setState({
            selectedFile: e.target.files[0]
        });
        const formData = new FormData();
        formData.append('file', this.state.selectedFile);
        //Append the rest data then send
        axios({
           method: 'post',
           url: 'myurl',
           data: formData,
           headers: {'Content-Type': 'multipart/form-data' }
        })
        .then(function (response) {
           //handle success
           console.log(response);
        }, 
        function(error) { 
           // handle error 
        });