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Spring MVC Restful Multipart Form Not Working

I've created a Restful service with Spring MVC as shown below. I called it using Postman. I placed a breakpoint on 'return "hello World"'. There's no hit on the breakpoint with the error message "Required request part 'file' is not present".
However, if I comment out the '#RequestParam("file")' annotation, the breakpoint is hit with the parameter "file" being null.
What could have gone wrong? Very puzzled.
#RestController
#RequestMapping("/dp")
public class DpWebService implements IDpWebService {
#Override
#Bean
public MultipartConfigElement multipartConfigElement() {
return new MultipartConfigElement("");
}
#Override
#Bean
public MultipartResolver multipartResolver() {
org.springframework.web.multipart.commons.CommonsMultipartResolver multipartResolver = new org.springframework.web.multipart.commons.CommonsMultipartResolver();
multipartResolver.setMaxUploadSize(1000000);
return multipartResolver;
}
#Override
#RequestMapping(path = "/send", method = RequestMethod.POST, consumes = "multipart/form-data")
public String sendManifest(#RequestParam("file") MultipartFile file) {
return "Hello World";
}
}
Postman
Postman Header

Check your POSTMAN request Configuration. I think you have not changed the input type to File from Text. Uploading images, check the images. Hover the mouse over that area in Postman and select File from the drop-down menu.
Having Beans defined in your RestController is not a good design. Please separate out a Configuration class with #Configuration annotation and define your beans. The reasons being: Single Responsibility Principle - each class should only do about one thing.
https://java-design-patterns.com/principles/#single-responsibility-principle

#RequestParam might not be working for you because of the nature of the data that is contained in the file that you are sending through the request. RequestParam is likely to be used with name-value form fields. For complex data like json/xml it is advisable to use #RequestPart instead.
Instead of the #RequestParam annotation use the #RequestPart annotation.
Annotation that can be used to associate the part of a
"multipart/form-data" request with a method argument.
Try using it like :
#RestController
#RequestMapping("/dp")
public class DpWebService implements IDpWebService {
#Override
#Bean
public MultipartConfigElement multipartConfigElement() {
return new MultipartConfigElement("");
}
#Override
#Bean
public MultipartResolver multipartResolver() {
org.springframework.web.multipart.commons.CommonsMultipartResolver multipartResolver = new org.springframework.web.multipart.commons.CommonsMultipartResolver();
multipartResolver.setMaxUploadSize(1000000);
return multipartResolver;
}
#Override
#RequestMapping(path = "/send", method = RequestMethod.POST, consumes = "multipart/form-data")
public String sendManifest(#RequestPart("file") MultipartFile file) {
return "Hello World";
}
}
Also make sure that the request from the postman is getting triggered correctly :
Remove any un wanted request params from postman.
Make sure that under 'Body' tab the form-data is selected. Also make
sure that when selected the file in the key the name is provided as
'file' and type is also selected as file instead of text.

This is my working example.
#PostMapping("/uploadFile")
public UploadFileResponse uploadFile(#RequestParam("file") MultipartFile file) {
String fileName = fileStorageService.storeFile(file);
String fileDownloadUri = ServletUriComponentsBuilder.fromCurrentContextPath().path("/downloadFile/")
.path(fileName).toUriString();
return new UploadFileResponse(fileName, fileDownloadUri, file.getContentType(), file.getSize());
}
application.properties
## MULTIPART (MultipartProperties)
# Enable multipart uploads
spring.servlet.multipart.enabled=true
# Threshold after which files are written to disk.
spring.servlet.multipart.file-size-threshold=2KB
# Max file size.
spring.servlet.multipart.max-file-size=200MB
# Max Request Size
spring.servlet.multipart.max-request-size=215MB
## File Storage Properties
# Please change this to the path where you want the uploaded files to be stored.
file.upload-dir=C://Users//abc//Documents//

how to solve error = "page not found 404 during Spring Application"

I am trying to make a postRequest and trying to get the object from request but the code is not getting executed. It is not getting inside the method.
I have already tried adding #componentScan in config files and #EntityScan
#RestController
#RequestMapping("/api/verify")
#CrossOrigin(origins = "*")
public class Verify {
#PostMapping(path = "/members", consumes = "application/json")
public String verify(#RequestBody DeviceDetails device) {
try {
System.out.println(device.getIpAddress());
//return "1";
return "hi";
}
catch (Exception e) {
System.out.println(e);
return "hi from err";
}
}
I expect that it should print hi to console and it should print IP Address

You're using wrong method - get (in the screenshot from postman), whereas in your mapping you're defining a post endpoint: #PostMapping(path = "/members", consumes = "application/json"). You need to change it to GetMapping or simply use post in postman. Also - check the urls and bodies if they match.

The above code has a path of /api/verify/members but in postman, it is /api/verify/call. In Postman, please correct it to /api/verify/members, change GET method to the POST method, and also please check if the JSON body is proper. Once these are fixed it should work.

How to return an image in Spring Boot controller and serve like a file system

I've tried the various ways given in Stackoverflow, maybe I missed something.
I have an Android client (whose code I can't change) which is currently getting an image like this:
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.connect();
Where url is the location of the image (static resource on CDN). Now my Spring Boot API endpoint needs to behave like a file resource in the same way so that the same code can get images from the API (Spring boot version 1.3.3).
So I have this:
#ResponseBody
#RequestMapping(value = "/Image/{id:.+}", method = RequestMethod.GET, consumes = MediaType.ALL_VALUE, produces = MediaType.IMAGE_JPEG_VALUE)
public ResponseEntity<byte[]> getImage(#PathVariable("id")String id) {
byte[] image = imageService.getImage(id); //this just gets the data from a database
return ResponseEntity.ok(image);
}
Now when the Android code tries to get http://someurl/image1.jpg I get this error in my logs:
Resolving exception from handler [public
org.springframework.http.ResponseEntity
com.myproject.MyController.getImage(java.lang.String)]:
org.springframework.web.HttpMediaTypeNotAcceptableException: Could not
find acceptable representation
Same error happens when I plug http://someurl/image1.jpg into a browser.
Oddly enough my tests check out ok:
Response response = given()
.pathParam("id", "image1.jpg")
.when()
.get("MyController/Image/{id}");
assertEquals(HttpStatus.OK.value(), response.getStatusCode());
byte[] array = response.asByteArray(); //byte array is identical to test image
How do I get this to behave like an image being served up in the normal way? (Note I can't change the content-type header that the android code is sending)
EDIT
Code after comments (set content type, take out produces):
#RequestMapping(value = "/Image/{id:.+}", method = RequestMethod.GET, consumes = MediaType.ALL_VALUE)
public ResponseEntity<byte[]> getImage(#PathVariable("id")String id, HttpServletResponse response) {
byte[] image = imageService.getImage(id); //this just gets the data from a database
response.setContentType(MediaType.IMAGE_JPEG_VALUE);
return ResponseEntity.ok(image);
}
In a browser this just seems to give a stringified junk (byte to chars i guess). In Android it doesn't error, but the image doesn't show.

I believe this should work:
#RequestMapping(value = "/Image/{id:.+}", method = RequestMethod.GET)
public ResponseEntity<byte[]> getImage(#PathVariable("id") String id) {
byte[] image = imageService.getImage(id);
return ResponseEntity.ok().contentType(MediaType.IMAGE_JPEG).body(image);
}
Notice that the content-type is set for ResponseEntity, not for HttpServletResponse directly.

Finally fixed this... I had to add a ByteArrayHttpMessageConverter to my WebMvcConfigurerAdapter subclass:
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
final ByteArrayHttpMessageConverter arrayHttpMessageConverter = new ByteArrayHttpMessageConverter();
final List<MediaType> list = new ArrayList<>();
list.add(MediaType.IMAGE_JPEG);
list.add(MediaType.APPLICATION_OCTET_STREAM);
arrayHttpMessageConverter.setSupportedMediaTypes(list);
converters.add(arrayHttpMessageConverter);
super.configureMessageConverters(converters);
}

In case you don't know the file/mime type you can do this.... I've done this where i take an uploaded file and replace the file name with a guid and no extension and browsers / smart phones are able to load the image no issues.
the second is to serve a file to be downloaded.
#RestController
#RequestMapping("img")
public class ImageController {
#GetMapping("showme")
public ResponseEntity<byte[]> getImage() throws IOException{
File img = new File("src/main/resources/static/test.jpg");
return ResponseEntity.ok().contentType(MediaType.valueOf(FileTypeMap.getDefaultFileTypeMap().getContentType(img))).body(Files.readAllBytes(img.toPath()));
}
#GetMapping("thing")
public ResponseEntity<byte[]> what() throws IOException{
File file = new File("src/main/resources/static/thing.pdf");
return ResponseEntity.ok()
.header("Content-Disposition", "attachment; filename=" +file.getName())
.contentType(MediaType.valueOf(FileTypeMap.getDefaultFileTypeMap().getContentType(file)))
.body(Files.readAllBytes(file.toPath()));
}
}
UPDATE in java 9+ you need to add compile 'com.sun.activation:javax.activation:1.2.0' to your dependencies this has also been moved or picked up by jakarta.see this post

Using Apache Commons, you can do this and expose the image on an endpoint
#RequestMapping(value = "/image/{imageid}",method= RequestMethod.GET,produces = MediaType.IMAGE_JPEG_VALUE)
public #ResponseBody byte[] getImageWithMediaType(#PathVariable int imageid) throws IOException {
InputStream in = new ByteArrayInputStream(getImage(imageid));
return IOUtils.toByteArray(in);
}
All images will be served at endpoint /image/{imageid}

Test file upload Spring MVC

I would like to test file uploading by REST API. I found it quite confusing to send file as RequestParam instead of RequestBody.
Controller method:
#PostMapping(value = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
public
#ResponseBody
ResponseEntity<String> uploadFile(
#RequestParam(name = "file") MultipartFile multipartFile,
#RequestParam(name = "path") String path) {
logger.debug("File upload REST requested");
return new ResponseEntity<>(fileService.uploadFile(
multipartFile, path),
HttpStatus.OK);
}
1.Now I would like to test it and I've used mocks. While debugging it, I see that mock service working but method exactly with this arguments is not invoked, so the test if failed. How could I handle this?
#Test
public void testUploadFile() throws Exception {
String mockName = "mock";
MockMultipartFile mockMultipartFile = new MockMultipartFile(mockName, mockName.getBytes());
when(mockFileService.uploadFile(mockMultipartFile, rootDir)).thenReturn("success");
mockMvc.perform(MockMvcRequestBuilders.fileUpload("/files/upload")
.file("file", mockMultipartFile.getBytes())
.param("path", rootDir))
.andExpect(status().isOk())
.andExpect(content().string("success"));
verify(mockFileService, times(1)).updateFile(mockMultipartFile, rootDir);
verifyNoMoreInteractions(mockFileService);
}
2.How could I test this with Postman? I see that I can send file in Body, but how could I send it as param?
EDIT:
I've changed the method, but the problem is not there:
Argument(s) are different! Wanted:
mockFileService.uploadFile(
org.springframework.mock.web.MockMultipartFile#61bd0845,
"/"
);
Looks like method are using 2 instances of MockMultipartFile. And the second question is still open, how could this method be tested from Postman?

Yes, the test case fails, because
the problem is in your test case at the end, you are verifying the call to updateFile() which is incorrect as in your controller you are using uploadFile(), you MUST use the same method to verify.
So, you need to change the verify line as below:
verify(mockFileService, times(1)). uploadFile(mockMultipartFile, rootDir);
In other words, Mockito verify validates the number of times a method is invoked as you are trying to verify the call on a different method (not being used in controller), it is failing.

Ajax call to Spring MVC controller redirects page instead of returning value

I'm a little bit confused. I'm writing an MVC application and have a simple controller like this:
#Controller
public class ProfileController {
final String DEFAULT_MALE_AVATAR = "../resources/graphics/avatarMan.PNG";
final String DEAULT_FEMALE_AVATAR = "../resources/graphics/avatarWoman.PNG";
#Autowired
UserService userService;
#RequestMapping(value = "/profile", method = RequestMethod.GET)
public String index() {
return "user/profile";
}
#RequestMapping(value = "profile/getavatar", method = RequestMethod.GET)
public #ResponseBody String getLoggedUserAvatar() {
String userMail = SecurityContextHolder.getContext()
.getAuthentication().getName();
User loggedUser;
if (userMail != null) {
loggedUser = userService.findUserByEmail(userMail);
return loggedUser.getAvatar();
} else {
return DEFAULT_MALE_AVATAR;
}
}
I've also got a simple js file called with "onload" in my body html tag while entering /profile section.
function init() {
var url = "profile/getavatar";
$.ajax({
url : url
}).then(function(data) {
avatarLink = data;
loadAvatar(avatarLink);
});
function loadAvatar(avatarLink){
$("#userAvatar").attr("src", avatarLink);
}
}
And for some strange reason I get ridirected to "profile/getavatar" and the page contains text with value returned by getLoggedUserAvatar(). The funny thing is I've also got some other controllers to other sections with almost the same js files and controllers - and they work like a charm.
What am I missing?

I hope when you hit the URL directly, you are getting expected response. If that is not happening, then there is something else wrong. If you are getting proper response when you directly hit the url in browser, then try doing the below when doing the ajax call. It passes the content type that is expecting back from the server.
function init() {
var url = "profile/getavatar";
$.ajax({
url : url,
dataType: "json"
}).then(function(data) {
avatarLink = data;
loadAvatar(avatarLink);
});
function loadAvatar(avatarLink){
$("#userAvatar").attr("src", avatarLink);
}
}

If you are using spring 4, Please make sure that you have Jakson jars in your dependency library. framework will automatically pickup the content negotiator as JSON and will find for the Jakson jars in the background to transport JSON to server and get JSON data back from server
use JAXB jars , in case you need to handle XML as content negotiator.