Is it possible to use resttemplate to upload file in azure blob storage - Java

Question

Is there a way to upload files to Azure blob storage using rest template in Java - Spring framework ? I see all examples using SDK and it was successful but we are told not to use SDK - Java. I know question is 10,000 feet high, but any pointers/direction will help a lot.

Answer 1

No idea why not to use SDK, Also no idea who might be told you.

Anyway, Yes you can use RestTemplate or even better webClient.

All you have to do is to map the request sent with the SDK to the cloud.

You have to add header authentication manually. serialize the file I suppose.

And it's a lot of work when you do have a supported SDK for client.

For example , here is a simple request sent with WebClient for Redmine server

String url = "http://localhost:3001/projects.json"; //Redmine local server
RestTemplate restTemplate = new RestTemplate();
JSONObject object = new JSONObject();   //Json object that will need to be sent to redmine
object.put("name", "dummyName");        // Should look like this
object.put("identifier", "dummyId");    // {"project":{"identifier":"dummyId","name":"dummyName"}}
JSONObject body = new JSONObject();     
body.put("project", object);            
String plainCreds = "user:bitnami1"; // default basic auth encoding
byte[] plainCredsBytes = plainCreds.getBytes();
byte[] base64CredsBytes = Base64.encodeBase64(plainCredsBytes);
String base64Creds = new String(base64CredsBytes);
HttpHeaders headers = new HttpHeaders();
headers.add("Authorization", "Basic " + base64Creds); 
headers.add("Content-Type", "application/json");
RequestEntity<JSONObject> requestEntity = RequestEntity
                .post(new URI(url))
                .accept(MediaType.APPLICATION_JSON)
                .headers(headers)
                .body(body);
ResponseEntity<String> r = restTemplate.exchange(requestEntity, String.class);

And this is who the same example will look like using RestTemplate

String url = "http://localhost:3001/projects.json"; //Redmine local server
RestTemplate restTemplate = new RestTemplate();
JSONObject object = new JSONObject();   //Json object that will need to be sent to redmine
object.put("name", "dummyName");        // Should look like this
object.put("identifier", "dummyId");    // {"project":{"identifier":"dummyId","name":"dummyName"}}
JSONObject body = new JSONObject();     
body.put("project", object);            
String plainCreds = "user:bitnami1"; // default basic auth encoding
byte[] plainCredsBytes = plainCreds.getBytes();
byte[] base64CredsBytes = Base64.encodeBase64(plainCredsBytes);
String base64Creds = new String(base64CredsBytes);
HttpHeaders headers = new HttpHeaders();
headers.add("Authorization", "Basic " + base64Creds); 
headers.add("Content-Type", "application/json");
HttpEntity<Object> entity = new HttpEntity<Object>(body, headers);
ResponseEntity<String> result = restTemplate.exchange("http://localhost:3001/projects.json",
                HttpMethod.POST,
                entity,
                String.class);

Both of these, Were only possible because am trying to match this curl request

curl --location --request POST 'localhost:3001/projects.json' \
--header 'Authorization: Basic dXNlcjpiaXRuYW1pMQ==' \
--header 'Content-Type: application/json' \
--data-raw '{"project":{"identifier":"dummyId","name":"dummyName"}}'

So once You know what the request looks like, You can use RestTemplate or WebClient, or any other similar class to build up your request.