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

Question

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 im

Answer 1

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 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 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