FileUploadController.java

package io.spring.guides.uploading_files;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

@Controller
public class FileUploadController {
    @RequestMapping(value = "/upload", method = RequestMethod.GET)
    public
    @ResponseBody
    String provideUploadInfo() {
        return "You can upload a file by posting to this same URL.";
    }

    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    public
    @ResponseBody
    String handleFileUpload(@RequestParam("name") String name, @RequestParam("file") MultipartFile file) {
        if (!file.isEmpty()) {
            try {
                try (BufferedOutputStream stream = new BufferedOutputStream(new FileOutputStream(new File(name)))) {
                    stream.write(file.getBytes());
                }
                return "You successfully uploaded " + name + "!";
            } catch (IOException e) {
                return "You failed to upload " + name + " => " + e.getMessage();
            }
        } else {
            return "You failed to upload " + name + " because the file was empty.";
        }

    }
}