在 Java 中將列表作為參數傳遞

Question

我有一個清單。

[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)]

我需要迭代並從此列表中獲取 id 並將每個 id 作為參數傳遞給 API 調用 - attachments/{{attachmentid}}/retrieve 。

我能夠檢索 ids 並將它們存儲在 Map 中。 （不確定在這里使用 Map 是否正確？）這是我編寫的代碼片段，但之后我無法繼續。

  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 調試 18644 --- [nio-8081-exec-2] cfphsiPlServiceImpl：附件 ID：{id=ATT-mXRJB-BmVzs} 2020-08-27：294G9166 --- [nio-8081-exec-2] cfphsiPlServiceImpl : 附件 ID : {id=ATT-y7Qr2-8RqkW} 2020-08-27 22:21:49.967 DEBUG 18644 --- [nio-8081-exec-2] cfphsiPlServiceImpl：附件 ID：{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());

我能夠打印附件 id - 但是我如何將它們作為參數傳遞給這樣的 api 調用 -attachments/{{attachmentid}}/retrieve

Answer 1

請使用foreach遍歷map並調用http調用方法

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);
                });

使用參數 id（以及您需要的其他參數）創建 Http 調用方法並使用方法進行調用。

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

為什么不直接遍歷Attachments列表並從每個Attachment檢索 id 並將其傳遞給 UriComponentsBuilder 以構建 URI。 您不需要額外的數據結構來保存 Id。

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.
   }
}