Struts 2 problem to upload a document problem with ajax

Question

I have a problem to upload a file with my Struts 2 app.

I have this:

<div class="form-group">
  <label for="file">my file</label>
  <input type="file" class="form-control-file" name="releveFile" id="file">
</div>

with this function:

const fileUpload= $('#file')[0].files[0];
const formData = new FormData();
formData.append('fileUpload', fileUpload);
$.ajax({
   url: '${pageContext.request.contextPath}/projet.releves.upload.action',
   type: "POST",
   enctype: 'multipart/form-data',
   data : formData,
   cache: false,
   processData: false,
   contentType: false,
   success: function (data) {
         tata.success('', 'Releve créé avec succès');
         $('#releveModal').modal('hide');
         this.loadReleves();
   },
   error: function (err) {
         tata.error(err);
   }
});

my Struts action is:

@Action(value = "projet.releves.upload", results = {
            @Result(name = "success", type = "json", params = {"root", "dto"})
    }, interceptorRefs =  @InterceptorRef(value = "fileUpload", params = {"maximumSize","100000000"}))
    public String upload() {
        System.out.println("file =" + fileUpload);
        System.out.println("file =" + uploadFileName);
        return SUCCESS;
    }

When I click on upload, I get a 200 and I see my file data in the request. However, the

System.out.println("file =" + fileUpload); 

is always file = null.

Could you help me to fix this?

Answer 1

The file field is populated by the fileUpload interceptor. More about these and how it works in Struts 2 see File Upload.

The fileUpload interceptor will use setter injection to insert the uploaded file and related data into your Action class. For a form field named upload you would provide the three setter methods shown in the following example:

Example Action class:

package com.example;

import java.io.File;
import com.opensymphony.xwork2.ActionSupport;

public class UploadAction extends ActionSupport {
 private File file;
 private String contentType;
 private String filename;

 public void setUpload(File file) {
    this.file = file;
 }

 public void setUploadContentType(String contentType) {
    this.contentType = contentType;
 }

 public void setUploadFileName(String filename) {
    this.filename = filename;
 }

 public String execute() {
    //...
    return SUCCESS;
 }

}

Answer 2

                        Hiii, can you please try with below piece of code...                            
                        //ajax sample data post
                        var myform = document.getElementById("formId");
                        var fd = new FormData(myform);

                        console.log("Processing... Please wait...");

                        $.ajax({
                            url: "upload",
                            type: "POST",             
                            data : fd,
                            async:true,
                            cache: false,
                            dataType: "json",
                            processData: false,
                            contentType: false,
                            success: function(json) {
                                 if(json.error)
                                     console.log("Error");
                                 else
                                 {   
                                    console.log("Upload Successful");
                                 } 
                            },
                            error: function(err) {
                                 console.log("Exception Occured.");
                            }
                        });

                        //java sample code 
                        private File releveFile;
                        private String releveFileFileName;
                        public String upload() {
                           System.out.println("file =" + releveFile);
                           System.out.println("file name =" + releveFileFileName);
                         return SUCCESS;
                        }