Return a file from Controller in Spring - spring

Question

I am new to spring. I have a controller with a RequestMapping for several GET parameters. They return a String .
But one method needs to return a file in the "/res/" folder. How do I do that?
#RequestMapping(method = RequestMethod.GET,value = "/getfile")
public #ResponseBody
String getReviewedFile(#RequestParam("fileName") String fileName)
{
return //the File Content or better the file itself
}
Thanks

Answer 1

Thanks to #JAR.JAR.beans. Here is the link: Downloading a file from spring controllers
#RequestMapping(value = "/files/{file_name}", method = RequestMethod.GET)
#ResponseBody
public FileSystemResource getFile(#PathVariable("file_name") String fileName) {
return new FileSystemResource(myService.getFileFor(fileName));
}

Answer 2

May be this will help
#RequestMapping(method = RequestMethod.GET,value = "/getfile")
public #ResponseBody
void getReviewedFile(HttpServletRequest request, HttpServletResponse response, #RequestParam("fileName") String fileName)
{
//do other stuff
byte[] file = //get your file from the location and convert it to bytes
response.reset();
response.setBufferSize(DEFAULT_BUFFER_SIZE);
response.setContentType("image/png"); //or whatever file type you want to send.
try {
response.getOutputStream().write(image);
} catch (IOException e) {
// Do something
}
}

Answer 3

Another way, though Jatin's answer is way cooler :
//Created inside the "scope" of #ComponentScan
#Configuration
public class AppConfig extends WebMvcConfigurerAdapter {
#Value("${files.dir}")
private String filesDir;
#Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry
.addResourceHandler("/files/**")
.addResourceLocations("file:" + filesDir);
}
}
Lifted from:
http://www.baeldung.com/spring-mvc-static-resources
https://spring.io/blog/2014/07/24/spring-framework-4-1-handling-static-web-resources

Answer 4

This works like a charm for me:
#RequestMapping(value="/image/{imageId}", method = RequestMethod.GET)
public ResponseEntity<byte[]> getImage(#PathVariable String imageId) {
RandomAccessFile f = null;
try {
f = new RandomAccessFile(configs.getImagePath(imageId), "r");
byte[] b = new byte[(int)f.length()];
f.readFully(b);
f.close();
final HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.IMAGE_PNG);
return new ResponseEntity<byte[]>(b, headers, HttpStatus.CREATED);
} catch (Exception e) {
return null;
}
}

Answer 5

If you are working on local Windows machine this could be useful for you:
#RequestMapping(value="/getImage", method = RequestMethod.GET)
#ResponseBody
public FileSystemResource getUserFile(HttpServletResponse response){
final File file = new File("D:\\image\\img1.jpg");
response.reset();
response.setContentType("image/jpeg");
return new FileSystemResource(file);
}
for testing your code you can use Postman "Use Send And Download not just send"
Another Approach to return byte:
#GetMapping("/getAppImg")
#ResponseBody
public byte[] getImage() throws IOException {
File serveFile = new File("image_path\\img.jpg");
return Files.readAllBytes(serveFile.toPath());
}