在Java中使用供應商流<InputStream>給予澤西島響應

Question

所以我現在有一種醜陋的情況。我有一個包含「getAllData」方法的類版本。該方法返回InputStream的Supplier。

public class Revision { 
    private String id; 
    private Supplier<InputStream> allData; 

    public Revision(String id, Supplier<InputStream> allData) { 
     this.id = id; 
     this.allData = allData; 
    } 

    public getAllData() { 
     return allData; 
    } 
} 

比方說，我有2個修訂。他們宣稱，像這樣：

Supplier<InputStream> revisionValue1 =() -> new ByteArrayInputStream(
      "{\"name\":\"George\", \"state\":\"Colorado\", \"Exp\":\"lots\"}".getBytes()); 
Revision revision1 = new Revision("Id1", revisionValue1); 

Supplier<InputStream> revisionValue2 =() -> new ByteArrayInputStream(
      "{\"name\":\"Sean\", \"state\":\"New York\"}".getBytes()); 
Revision revision2 = new Revision("Id2", revisionValue2); 

而且他們放入地圖成員：

Map<String, Revision> revisions = new HashMap<>(); 
revisions.put("Id1", revision1); 
revisions.put("Id2", revision2); 

電流的方法（這本身可能不是寫得很好）返回流：

public Stream<Revision> getRevisions() { 
    return revisions.values().stream(); 
} 

現在在我的Jersey代碼中，我需要弄清楚如何將這些值作爲Json格式的響應返回。所以結果應該是這樣的：

[ 
{ 
    "name": "George", 
    "state": "Colorado", 
    "Exp": "lots" 
}, 
{ 
    "name": "Sean", 
    "state": "New York" 
} 
] 

我試圖做到這一點，即使作爲純文本，這是行不通的。我想要的是：

@Produces(MediaType.TEXT_PLAIN) 
public Response getRevisions(...) { 

    Stream<Revision> revisionObjects = getRevisions(); 

    // each Revision option has a getAllData() method that needs called, which returns Supplier<InputStream> 
    // each Supplier<InputStream> contains, essentially, a Json record 

    // attempt at creating a StreamingOutput that can be sent as a response 
    if (revisionObjects != null) { 
     StreamingOutput stream = os -> { 
      Writer writer = new OutputStreamWriter(os); 
      Iterator<Revision> revisionIterator = revisionObjects.iterator(); 
      while (revisionIterator.hasNext()) { 
       Revision next = revisionIterator.next(); 
       writer.write(next.getAllData().get().toString()); 
      } 
      writer.flush(); 
     }; 
     return Response.ok(stream).build(); 
    } 
    return Response.noContent().build(); 
} 

這是返回結果一樣：

java.io.ByteArrayInputStream@7de636java.io.ByteArrayInputStream@ba0b09 

這我假設是因爲有需要是「的toString（）」方法之前一個額外的步驟作家。

對不起，這是多久，我只是想提供的細節。有誰知道如何讓這個工作？理想情況下，我希望它能用JSON做出迴應，但即使是純文本也是一個巨大的進步。

P.S.我仍然試圖圍繞InputStreams和OutputStreams進行封裝，所以很有可能，我有一些不合邏輯的東西。

Answer 1

@Produces(MediaType.TEXT_PLAIN) 
public Response getRevisions(...) { 

    Stream<Revision> revisionObjects = getRevisions(); 

    // each Revision option has a getAllData() method that needs called, which returns Supplier<InputStream> 
    // each Supplier<InputStream> contains, essentially, a Json record 

    // attempt at creating a StreamingOutput that can be sent as a response 
    if (revisionObjects != null) { 
      Iterator<Revision> revisionIterator = revisionObjects.iterator(); 
      List<JSONObject> revisionsResponse = new ArrayList<JSONObject>(); 
      while (revisionIterator.hasNext()) { 
       BufferedReader streamReader = new BufferedReader(new InputStreamReader(revisionIterator.next().getAllData().get(), "UTF-8")); 
       StringBuilder responseStrBuilder = new StringBuilder(); 

       String inputStr; 
       while ((inputStr = streamReader.readLine()) != null) 
         responseStrBuilder.append(inputStr); 
       revisionsResponse.add(new JSONObject(responseStrBuilder.toString()); 
      } 

      return Response.ok(revisionsResponse).build(); 
    } 
    return Response.noContent().build(); 
}