如何在 Spring 引导中发送图像作为响应？

Question

I am a beginner with spring boot (restController) and angular I want to send an image to my client(angular) with this method:

@RestController public class ProductRestController { 
    @Autowired private ProductRepository pr;
    @GetMapping (path = "/ photoProduit / {id}", produces = org.springframework.http.MediaType.IMAGE_PNG_VALUE)
     public byte [] getPhoto (@PathVariable Long id) throws IOException { 
        Product p = pr.findById (id) .get (); return Files.readAllBytes (Paths.get (System.getProperty ("user.home") + "/ ecom / produits /" + p.getPhotoName ()));
        
    }
 }

But the URL returns me a code 500 with this error

There was an unexpected error 
(type = Internal Server Error, status = 500). C: \ Users \ Gonan \ ecom \ products \ unknow.png java.nio.file.NoSuchFileException: C: \ Users \ Gonan \ ecom \ produits \ unknow.png

Can you help me, please??

Answer 1

As per the exception you have posted, it looks like the image path you trying to read is not found.

Also there are few corrections to the method, here is how i have done this:

import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.Resource;

@GetMapping(value = "/image", produces = MediaType.IMAGE_JPEG_VALUE)
    public ResponseEntity<Resource> image() throws IOException {
        final ByteArrayResource inputStream = new ByteArrayResource(Files.readAllBytes(Paths.get(
                "/home/silentsudo/Videos/dum111111b.jpg"
        )));
        return ResponseEntity
                .status(HttpStatus.OK)
                .contentLength(inputStream.contentLength())
                .body(inputStream);

    }

Please make sure that the URI to Paths.get(...) is a valid otherwise you will still get java.nio.file.NoSuchFileException