Synopsis so far

I came across a situation where I want to implement FileUpload processing via JavaScript in Nanika made with Apache Wicket.

Rest in Wicket is wicketstuff-restannotations. There is an ancestor who also posted an article on Qiita, and you can see how to use it by looking at the linked document, but a sample of FileUpload Is not found.

That's why I decided to leave a note that it seems to be a power technique for the time being, but it worked with this.

Version

Wicket 8.1.0
wicketstuff-restannotations 8.1.0 --Commons FileUpload Banzai --No explanation on how to use wicketstuff-restannotations

Implementation

Caller. Come on. I don't think it's JQuery anymore, but it's Wicket.

`test.html`


<!DOCTYPE html>
<html>
<body>
<input type="file" id="file-select" style="display:none">
<button id="file-button">File selection</button>
<script>
$('#file-button').click(function(e) {
  $("#file-select").click();
});
$("#file-select").change(function(e) {
  var file = e.target.files;
  if(file.length > 0) {
    var form = new FormData();
    form.append('image', file[0]);
    var settings = {
      "async": false,
      "crossDomain": false,
      "url": "fileUpload",
      "method": "POST",
      "dataType": "text",
      "processData": false,
      "contentType": false,
      "data": form
    }
    $.ajax(settings).done(function (response) {
      if(result.success) {
        alert(response);
      }
    });
  }
});
</script>
</body>
</html>

RestResource。 Is it the immediate goal to get the FileItem of FileUpload here? I think that the response in JSON is normal, but I omit that part. It doesn't matter, but I'm not sure why Abstract Rest Resource is a generic type.

`FileUploadResource.java`


package yamane.rest;

import org.apache.commons.fileupload.FileItem;
import org.wicketstuff.rest.annotations.MethodMapping;
import org.wicketstuff.rest.annotations.parameters.RequestBody;
import org.wicketstuff.rest.contenthandling.mimetypes.RestMimeTypes;
import org.wicketstuff.rest.resource.AbstractRestResource;
import org.wicketstuff.rest.utils.http.HttpMethod;

public class FileUploadResource extends AbstractRestResource<FileUploadSerialDeserial> {

  public FileUploadResource() {
    super(new FileUploadSerialDeserial());
  }

  @MethodMapping(
    value = "/fileUpload",
    httpMethod = HttpMethod.POST,
    produces = RestMimeTypes.TEXT_PLAIN
  )
  public String saveImage(@RequestBody FileItem item) {
    //If you can get FileItem, you win!
    return item.getFieldName();
  }
}

The part of the liver, IWebSerialDeserial. Well, I just fetch HttpServletRequest and parse it with FileUpload. It is quite appropriate except for the corresponding processing. Corresponding processing is also reasonably appropriate. It doesn't matter, but what about the name SerialDeserial?

`FileUploadSerialDeserial.java`


package yamane.rest;

import java.io.File;
import java.util.List;

import javax.servlet.ServletContext;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.protocol.http.WebApplication;
import org.apache.wicket.protocol.http.servlet.ServletWebRequest;
import org.apache.wicket.request.http.WebRequest;
import org.apache.wicket.request.http.WebResponse;
import org.wicketstuff.rest.contenthandling.IWebSerialDeserial;

public class FileUploadSerialDeserial implements IWebSerialDeserial {

  DiskFileItemFactory factory = new DiskFileItemFactory();

  FileUploadSerialDeserial() {
    ServletContext context = WebApplication.get().getServletContext();
    File repository = (File) context.getAttribute("javax.servlet.context.tempdir");
    factory.setRepository(repository);
  }

  @Override
  public void objectToResponse(Object str, WebResponse response, String mimeType) throws WicketRuntimeException {
    ServletResponse sResponse = (ServletResponse) response.getContainerResponse();
    sResponse.setCharacterEncoding("UTF-8");
    response.write((CharSequence) str);
  }

  @Override
  @SuppressWarnings("unchecked")
  public <T> T requestToObject(
    WebRequest wRequest,
    Class<T> argClass,
    String mimeType) throws WicketRuntimeException {
    try {
      ServletWebRequest sRequest = (ServletWebRequest) wRequest;
      HttpServletRequest request = sRequest.getContainerRequest();
      ServletFileUpload fileUpload = new ServletFileUpload(factory);
      List<FileItem> items = fileUpload.parseRequest(request);
      return !items.isEmpty() ? (T) items.get(0) : null;
    } catch (FileUploadException e) {
      throw new WicketRuntimeException(e);
    }
  }

  @Override
  public boolean isMimeTypeSupported(String mimeType) {
    return true;
  }
}

Up to here for this time

So, I was able to get the file via JavaScript safely. It's a rough article, but please forgive me for taking notes.

[JAVA] FileUpload with Rest on Apache Wicket