在 Java 中将列表作为参数传递

Question

I have a list this.

[Attachments(filename=a.json,  id=ATT-mXRJB-BmVzs, contentType=application/json),
 Attachments(filename=b.pdf,  id=ATT-y7Qr2-8RqkW, contentType=application/pdf ),
 Attachments(filename=c.docx,  id=ATT-mYh3z-3YJ37, contentType=application/vnd.openxmlformats-officedocument.wordprocessingml.document)]

I need to iterate and get ids from this list and pass each id as parameter for an API call - attachments/{{attachmentid}}/retrieve .

I am able to retrieve ids and store them in a Map . (Not sure if using Map is correct here?) This is the code snippet I have written , But I am unable to proceed after that.

  Map<String, String> attachmentMap = new HashMap<String, String>();
    Optional.ofNullable(attList)
                .orElse(Collections.emptyList())
                .forEach(aList -> {
                     attachmentMap.put("id", aList.getId());
                    LOGGER.debug("Attachment ids : {}",attachmentMap);
                });
    

        

2020-08-27 22:21:49.967 DEBUG 18644 --- [nio-8081-exec-2] cfphsiPlServiceImpl : Attachment ids : {id=ATT-mXRJB-BmVzs} 2020-08-27 22:21:49.967 DEBUG 18644 --- [nio-8081-exec-2] cfphsiPlServiceImpl : Attachment ids : {id=ATT-y7Qr2-8RqkW} 2020-08-27 22:21:49.967 DEBUG 18644 --- [nio-8081-exec-2] cfphsiPlServiceImpl : Attachment ids : {id=ATT-mYh3z-3YJ37}

  URI uri = UriComponentsBuilder.
                    .pathSegment(ATTACHMENTS)
                    .pathSegment(?)   //what to give here? 
                    .pathSegment(RETRIEVE)
                    .build().toUri();
        LOGGER.debug("URL to Retrieve  : {}", uri.toString());

I am able to print attachment ids - but how do I pass each of them as parameter to an api call like this - attachments/{{attachmentid}}/retrieve

Answer 1

Please use foreach to iterate through map and call the http call method

Map<String, String> attachmentMap = new HashMap<String, String>();
    Optional.ofNullable(attList)
                .orElse(Collections.emptyList())
                .forEach(aList -> {
                     attachmentMap.put("id", aList.getId());
                     httpCall(aList.getId());
                    LOGGER.debug("Attachment ids : {}",attachmentMap);
                });

create Http call method with parameter id(also other params you need) and use method to call.

public static void httpCall(id){
  URI uri = UriComponentsBuilder.
                    .pathSegment(ATTACHMENTS)
                    .pathSegment(id)   //what to give here? 
                    .pathSegment(RETRIEVE)
                    .build().toUri();
        LOGGER.debug("URL to Retrieve  : {}", uri.toString());
}

Answer 2

Why not just loop over Attachments list directly and retrieve the id from each Attachment and pass it to the UriComponentsBuilder to build the URI. You don't need an extra data structure to hold the Ids.

List<URI> uriList = new ArrayList<>();

for(Attachment attachment: Attachments){
   String id = attachment.getId();
   if (id != null) {
       URI uri = UriComponentsBuilder.
                .pathSegment(ATTACHMENTS)
                .pathSegment(id)
                .pathSegment(RETRIEVE)
                .build().toUri();
       uriList.add(uri); // or you can call the uri directly from here using your http client.
   }
}