在上传多个MultipartFile文件的Spring Boot中遇到错误。

huangapple
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英文:

getting error on springboot while upload list of multipartfile

问题

  1. 我正在尝试上传多个文件，在这样做时遇到了问题。请有人指出可能出了什么问题吗？
  3. 我在此附上了我代码中相关的片段，以便更好地进行调试。
  5. **HTML代码**
  7.     <label>
  8.         欢迎 {{name}}，欢迎来到新的应用。
  9.     </label>
  10.     <div>
  11.         <input type="file" multiple placeholder="选择要上传的文件" accept=".xlsx" (change)=selectedfiles($event)>
  12.     </div>
  14. **上传逻辑**
  16.     selectedfiles(event){
  17.     
  18.         this.selectedxlfiles=event.target.files;
  19.     
  20.         this.fileandinstancekeyobj.filetoupload=this.selectedxlfiles;
  21.         this.fileandinstancekeyobj.instancekey=this.instancekey;
  22.     
  23.         this.uploadservice.uploadtoserver(this.fileandinstancekeyobj).subscribe(result=>{
  24.           console.log(result);
  25.         })
  26.     
  27.       }
  29. **上传服务**
  31.     uploadtoserver(selectedfileandinstacekeyobj): Observable<HttpEvent<{}>>{
  32.     
  33.          let url:string=environment.url+'uploadfile';
  34.         const newrequest=new HttpRequest('POST',url,selectedfileandinstacekeyobj,{
  35.           reportProgress:true,
  36.           responseType:'text'
  37.         });
  38.     
  39.         return this.http.request(newrequest);
  40.       }
  42. **Spring Boot控制器**
  44.     @RestController
  45.     public class uploadcontroller {
  46.     
  47.     	@PostMapping("/uploadfile")
  48.     	public ResponseEntity<String> handleupload(@RequestBody uploaddto dto){
  49.     		
  50.     		System.out.println("成功");
  51.     		System.out.println(dto.getInstancekey()+" "+dto.getFiletoupload().length);
  52.     		
  53.     		
  54.     		return ResponseEntity.status(HttpStatus.OK).body("ok");
  55.     	}
  57. **上传DTO**
  58.     
  59.     import java.util.ArrayList;
  60.     import java.util.LinkedList;
  61.     import java.util.List;
  62.     
  63.     import org.springframework.web.multipart.MultipartFile;
  64.     
  65.     class uploaddto {
  66.     	
  67.     	List<MultipartFile> filetoupload;
  68.     	String instancekey;
  69.     	public uploaddto(List<MultipartFile> filetoupload, String instancekey) {
  70.     		super();
  71.     		filetoupload=new ArrayList<MultipartFile>();
  72.     		this.filetoupload = filetoupload;
  73.     		this.instancekey = instancekey;
  74.     	}
  75.     	public List<MultipartFile> getFiletoupload() {
  76.     		return filetoupload;
  77.     	}
  78.     	public void setFiletoupload(List<MultipartFile> filetoupload) {
  79.     		this.filetoupload = filetoupload;
  80.     	}
  81.     	public String getInstancekey() {
  82.     		return instancekey;
  83.     	}
  84.     	public void setInstancekey(String instancekey) {
  85.     		this.instancekey = instancekey;
  86.     	}
  87.     	
  88.     	
  89.     }
  90. 我收到以下错误消息
  92.     [org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: 
  93.     Cannot deserialize instance of `java.util.ArrayList<org.springframework.web.multipart.MultipartFile>` out of START_OBJECT token; 
  94.     nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: 
  95.     Cannot deserialize instance of `java.util.ArrayList<org.springframework.web.multipart.MultipartFile>` out of START_OBJECT token
  96.          at [Source: (PushbackInputStream); line: 1, column: 17] (through reference chain: com.example.demo.uploaddto["filetoupload"])]
  98. **欢迎任何建议**
英文:

I am trying to upload multiple files and I am facing an issue while doing so. Can someone please suggest what is wrong?

I am enclosing relevant snippets of my code to debug better.

html code

  1. &lt;label&gt;
  2.     welcome {{name}}, welcome to new app.
  3. &lt;/label&gt;
  4. &lt;div&gt;
  5.     &lt;input type=&quot;file&quot; multiple placeholder=&quot;Select Files to be upload&quot; accept=&quot;.xlsx&quot; (change)=selectedfiles($event)&gt;
  6. &lt;/div&gt;

upload logic

  1. selectedfiles(event){
  3.     this.selectedxlfiles=event.target.files;
  5.     this.fileandinstancekeyobj.filetoupload=this.selectedxlfiles;
  6.     this.fileandinstancekeyobj.instancekey=this.instancekey;
  8.     this.uploadservice.uploadtoserver(this.fileandinstancekeyobj).subscribe(result=&gt;{
  9.       console.log(result);
  10.     })
  12.   }

uploadservice

  1. uploadtoserver(selectedfileandinstacekeyobj): Observable&lt;HttpEvent&lt;{}&gt;&gt;{
  3.      let url:string=environment.url+&#39;uploadfile&#39;;
  4.     const newrequest=new HttpRequest(&#39;POST&#39;,url,selectedfileandinstacekeyobj,{
  5.       reportProgress:true,
  6.       responseType:&#39;text&#39;
  7.     });
  9.     return this.http.request(newrequest);
  10.   }

springboot controller

  1. @RestController
  2. public class uploadcontroller {
  4. 	@PostMapping(&quot;/uploadfile&quot;)
  5. 	public ResponseEntity&lt;String&gt; handleupload(@RequestBody uploaddto dto){
  6. 		
  7. 		System.out.println(&quot;sucessfull&quot;);
  8. 		System.out.println(dto.getInstancekey()+&quot; &quot;+dto.getFiletoupload().length);
  9. 		
  10. 		
  11. 		return ResponseEntity.status(HttpStatus.OK).body(&quot;ok&quot;);
  12. 	}

upload DTO

  1. import java.util.ArrayList;
  2. import java.util.LinkedList;
  3. import java.util.List;
  5. import org.springframework.web.multipart.MultipartFile;
  7. class uploaddto {
  8. 	
  9. 	List&lt;MultipartFile&gt; filetoupload;
  10. 	String instancekey;
  11. 	public uploaddto(List&lt;MultipartFile&gt; filetoupload, String instancekey) {
  12. 		super();
  13. 		filetoupload=new ArrayList&lt;MultipartFile&gt;();
  14. 		this.filetoupload = filetoupload;
  15. 		this.instancekey = instancekey;
  16. 	}
  17. 	public List&lt;MultipartFile&gt; getFiletoupload() {
  18. 		return filetoupload;
  19. 	}
  20. 	public void setFiletoupload(List&lt;MultipartFile&gt; filetoupload) {
  21. 		this.filetoupload = filetoupload;
  22. 	}
  23. 	public String getInstancekey() {
  24. 		return instancekey;
  25. 	}
  26. 	public void setInstancekey(String instancekey) {
  27. 		this.instancekey = instancekey;
  28. 	}
  29. 	
  30. 	
  31. }

I am receiving the following error

  1. [org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: 
  2. Cannot deserialize instance of `java.util.ArrayList&lt;org.springframework.web.multipart.MultipartFile&gt;` out of START_OBJECT token; 
  3. nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: 
  4. Cannot deserialize instance of `java.util.ArrayList&lt;org.springframework.web.multipart.MultipartFile&gt;` out of START_OBJECT token
  5.      at [Source: (PushbackInputStream); line: 1, column: 17] (through reference chain: com.example.demo.uploaddto[&quot;filetoupload&quot;])]

Any suggestion would be appreciated

答案1

得分: 1

以下是您要翻译的内容：

我正在添加这个答案，以便我可以帮助某人挽救他的一天，我所做的更改如下：

在 UploadController 中的更改

  1. this.selectedxlfiles = event.target.files;
  2. const data: FormData = new FormData();
  3. for (let i = 0; i < this.selectedxlfiles.length; i++) {
  4.   this.currentfile = this.selectedxlfiles[i];
  5.   data.append('selectedfile', this.currentfile);
  6. }
  7. data.append('instancekey', this.instancekey);
  8. this.uploadservice.uploadtoserver(data).subscribe(Response => {
  9.   console.log(Response);
  10. })

在 UploadService 中的更改

  1. uploadtoserver(data: FormData): Observable<HttpEvent<{}>> {
  3.   let url: string = environment.url + 'uploadfile';
  4.   const newrequest = new HttpRequest('POST', url, data, {
  5.     reportProgress: true,
  6.     responseType: 'text',
  7.   });
  9.   return this.http.request(newrequest);
  10. }

在 Spring Boot 控制器中的更改

  1. @RestController
  2. public class UploadController {
  4.   @PostMapping("/uploadfile")
  5.   public ResponseEntity<String> handleUpload(@ModelAttribute UploadDto dto) {
  7.     System.out.println("成功");
  8.     System.out.println(dto.getInstanceKey() + " " + dto.getFileToUpload().length);
  10.     return ResponseEntity.status(HttpStatus.OK).body("ok");
  11.   }
  12. }

控制器中唯一的更改是 @ModelAttribute。

英文:

I am adding this answer so that i could help someone save his day, what i did

change in uploadcontroller

  1. this.selectedxlfiles=event.target.files;
  2.   const data:FormData=new FormData();
  3. for(let i=0;i&lt;this.selectedxlfiles.length;i++){
  4.   this.currentfile=this.selectedxlfiles[i];
  5.   data.append(&#39;selectedfile&#39;,this.currentfile);
  6. }
  7. data.append(&#39;instancekey&#39;,this.instancekey);
  8. this.uploadservice.uploadtoserver(data).subscribe(Response=&gt;{
  9.   console.log(Response);
  10. })

changes in upload service

  1. uploadtoserver(data:FormData): Observable&lt;HttpEvent&lt;{}&gt;&gt;{
  3.       let url:string=environment.url+&#39;uploadfile&#39;;
  4.     // console.log(url);
  5.     //  const data: FormData=new FormData();
  6.     //  data.append(&#39;selectedfile&#39;,selectedfile);
  7.     //  data.append(&#39;instancekey&#39;,instancekey);
  8.     const newrequest=new HttpRequest(&#39;POST&#39;,url,data,{
  9.       reportProgress: true,
  10.       responseType: &#39;text&#39;,
  11.     });
  12.     
  14.     return this.http.request(newrequest);
  15.     //return this.http.post(url,selectedfiles);
  16.   }

changes in springboot controller

  1. @RestController
  2. public class uploadcontroller {
  4.     @PostMapping(&quot;/uploadfile&quot;)
  5.     public ResponseEntity&lt;String&gt; handleupload(@ModelAttribute uploaddto dto){
  6.         
  7.         System.out.println(&quot;sucessfull&quot;);
  8.         System.out.println(dto.getInstancekey()+&quot; &quot;+dto.getFiletoupload().length);
  9.         
  10.         
  11.         return ResponseEntity.status(HttpStatus.OK).body(&quot;ok&quot;);
  12.     }

the only change in controller @modelattribute

huangapple
  • 本文由 发表于 2020年9月21日 15:34:36
  • 转载请务必保留本文链接：https://go.coder-hub.com/63987945.html
  • angular8
  • java
  • spring-boot
  • typescript
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