在Java中使用供应商流<InputStream>给予泽西岛响应

Question

所以我现在有一种丑陋的情况。我有一个包含“getAllData”方法的类版本。该方法返回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; 
    } 
} 

比方说，我有2个修订。他们宣称，像这样：

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); 

而且他们放入地图成员：

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

电流的方法（这本身可能不是写得很好）返回流：

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

现在在我的Jersey代码中，我需要弄清楚如何将这些值作为Json格式的响应返回。所以结果应该是这样的：

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

我试图做到这一点，即使作为纯文本，这是行不通的。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(); 
} 

这是返回结果一样：

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

这我假设是因为有需要是“的toString（）”方法之前一个额外的步骤作家。

对不起，这是多久，我只是想提供的细节。有谁知道如何让这个工作？理想情况下，我希望它能用JSON做出回应，但即使是纯文本也是一个巨大的进步。

P.S.我仍然试图围绕InputStreams和OutputStreams进行封装，所以很有可能，我有一些不合逻辑的东西。

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(); 
}