Can't access image file from src/main/webapp/WEB-INF/resources/img in controller to display in jsp

Question

I try to display images from src/main/webapp/WEB-INF/resources/img/ folder (different from src/main/resources )

@Controller
@RequestMapping("/items")
public class ItemsController {
    @GetMapping( "/images/{itemId}")
    @ResponseBody
    public byte[] getItemImageById(@PathVariable long itemId) throws IOException {
           BufferedImage originalImage =
                ImageIO.read(
            new File("/WEB-INF/resources/img/" + itemId + ".png"));
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write( originalImage, "png", baos );
        baos.flush();
        byte[] imageInByte = baos.toByteArray();
        baos.close();
        return imageInByte;
    }
}

<img src='${pageContext.request.contextPath}/items/images/1'/>

It doesn't work - no image, but if I replace the path in the File constructor with absolute path like this: C://.../some_file.png it works fine.

Answer 1

You cannot go through a "File" to read in your image you need to go through the ServletContext .

@Controller
@RequestMapping("/items")
public class ItemsController {

   @Autowired
   ServletContext context;

    @GetMapping( "/images/{itemId}")
    @ResponseBody
    public byte[] getItemImageById(@PathVariable long itemId) throws IOException {
           BufferedImage originalImage =
                ImageIO.read(context.getResourceAsStream("/WEB-INF/resources/img/" + itemId + ".png"));

        // your original code
    }
}

Answer 2

Another approach that worked for me is:

@Autowired
ResourceLoader resourceLoader;

Resource resource =  resourceLoader.getResource(
                "/WEB-INF/resources/img/" + itemId + ".png");
String path = resource.getFile().getPath();
return Files.readAllBytes(Paths.get(path));