I update avatar image and display it but the avatar does not change in Spring Boot , why? - spring

Question

I use Spring boot to develop a website.I develop a function of uploading avatar image , when I update avatar image and display it but the avatar does not change and the image already has changed in the folder, why?
The problem is http cache?
my simple project:
dropbox link to my project
(note: you need to change the local path in TestingController)

Answer 1

You are not able to see the uploaded picture instantly because you save the image in the static files of your application. You are able to see the the saved image in your folder but not if you call your url. If you refresh your running project after uploading the file (project root and hit F5) you should be able to see it.
But the better solution would be that you have a #RequestMapping to load the picture and show it in browser.
Build on your project, try to use it like this:
import java.io.IOException;
import java.net.MalformedURLException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.stream.Stream;
import org.json.JSONObject;
import org.springframework.core.io.Resource;
import org.springframework.core.io.UrlResource;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
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;
#Controller
public class TestingController {
private final Path p = Paths.get("/Users/devin/Documents/workspace-sts-3.8.1.RELEASE/testing/src/main/resources/static/uploads/images");
#RequestMapping(value={ "/", "/home"})
public String home(){
return "home";
}
#RequestMapping(value = "/post_upload_avatar_file", method = RequestMethod.POST)
#ResponseBody
public Object uploadAvatarFile(#RequestParam("uploadfile") MultipartFile uploadfile) {
JSONObject resJsonData=new JSONObject();
try {
if(uploadfile.isEmpty()){
System.out.println("Empty");
}
Files.copy(uploadfile.getInputStream(), p.resolve(uploadfile.getOriginalFilename()));
resJsonData.put("status", 200);
resJsonData.put("message", "Success!");
resJsonData.put("data", uploadfile.getOriginalFilename());
}catch (Exception e) {
System.out.println(e.getMessage());
resJsonData.put("status", 400);
resJsonData.put("message", "Upload Image Error!");
resJsonData.put("data", "");
}
return resJsonData.toString();
}
#GetMapping("files/{filename:.+}")
#ResponseBody
public ResponseEntity<Resource> serverFile(#PathVariable String filename){
Resource file = loadAsResource(filename);
return ResponseEntity
.ok()
.body(file);
}
public Resource loadAsResource(String filename) {
try {
Path file = p.resolve(filename);
Resource resource = new UrlResource(file.toUri());
if(resource.exists() || resource.isReadable()) {
return resource;
}
else {
System.out.println("no file");
}
} catch (MalformedURLException e) {
System.out.println(e);
}
return null;
}
public Stream<Path> loadAll() {
try {
return Files.walk(p, 1)
.filter(path -> !path.equals(p))
.map(path -> p.relativize(path));
} catch (IOException e) {
System.out.println(e);
}
return null;
}
}
In this code I dont implement exception and error handling.
You can upload your picture like it was. And then you can call another url to receive the picture in your browser.
http://localhost:8080/files/testing.png
And the picture should be the response.
Please have a look to those two sources for a complete solution.
Spring file upload - backend
Spring file upload - frontend