Download a file using Spring RestTemplate

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.http.*;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RequestCallback;
import org.springframework.web.client.ResponseExtractor;
import org.springframework.web.client.RestTemplate;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.Collections;

@RestController
public class DownloadController {

    private final RestTemplate restTemplate;

    @Autowired
    public DownloadController(RestTemplateBuilder builder) {
        this.restTemplate = builder.build();
    }

    @GetMapping("/test-download-v1")
    public void download() throws IOException {
        String url = "http://img.championat.com/news/big/l/c/ujejn-runi_1439911080563855663.jpg";
        byte[] imageBytes = restTemplate.getForObject(url, byte[].class);
        Files.write(Paths.get("image.jpg"), imageBytes);
    }

}

@GetMapping("/test-download-v2")
public void downloadFile() throws IOException {
    String url = "http://img.championat.com/news/big/l/c/ujejn-runi_1439911080563855663.jpg";
    HttpHeaders headers = new HttpHeaders();
    headers.setAccept(Collections.singletonList(MediaType.APPLICATION_OCTET_STREAM));
    HttpEntity<String> entity = new HttpEntity<>(headers);
    ResponseEntity<byte[]> response = restTemplate.exchange(url, HttpMethod.GET, entity, byte[].class);
    Files.write(Paths.get("demo1.jpg"), response.getBody());
}

@GetMapping("/test-download-v3")
public void downloadFile() throws IOException {
    String url = "http://img.championat.com/news/big/l/c/ujejn-runi_1439911080563855663.jpg";
    // Optional Accept header
    RequestCallback requestCallback = request -> request
            .getHeaders()
            .setAccept(Arrays.asList(MediaType.APPLICATION_OCTET_STREAM, MediaType.ALL));

    // Streams the response instead of loading it all in memory
    ResponseExtractor<Void> responseExtractor = response -> {
        // Here you can write the inputstream to a file or any other place
        Path path = Paths.get("downloadv3.jpg");
        Files.copy(response.getBody(), path);
        return null;
    };
    restTemplate.execute(url, HttpMethod.GET, requestCallback, responseExtractor);
}