在Android中解析Json String（Feed RSS文件）

Question

How can I parse this piece of JSON code?

{
  "direction": "ltr",
  "id": "feed/http => //www.theverge.com/rss/full.xml",
  "title": "The Verge -  All Posts",
  "continuation": "CLKM0OyU0rYC",
  "self": [
    {
      " href": "https => //cloud.feedly.com/reader/3/stream/contents/feed%2Fhttp%3A%2F%2Fwww.theverge.com%2Frss%2Ffull.xml?n=20&unreadOnly=true"
    }
  ],
  "alternate": [
    {
      "href": "http://www.theverge.com/",
      "type": "text/html"
    }
  ],
  "updated": 1367539068016,
  "items": [
    {
      "id": "entryId",
      "unread": true,
      "categories": [
        {
          "id": "user/c805fcbf-3acf-4302-a97e-d82f9d7c897f/category/tech",
          "label": "tech"
        }
      ],
      "tags": [
        {
          "id": "user/c805fcbf-3acf-4302-a97e-d82f9d7c897f/tag/inspiration",
          "label": "inspiration"
        }
      ],
      "title": "NBC's reviled sci-fi drama 'Heroes' may get a second lease on life as Xbox Live exclusive",
      "published": 1367539068016,
      "updated": 1367539068016,
      "crawled": 1367539068016,
      "alternate": [
        {
          "href": "http://www.theverge.com/2013/4/17/4236096/nbc-heroes-may-get-a-second-lease-on-life-on-xbox-live",
          "type": "text/html"
        }
      ],
      "content": {
        "direction": "ltr",
        "content": "..."
      },
      "author": "Nathan Ingraham",
      "origin": {
        "streamId": "feed/http://www.theverge.com/rss/full.xml",
        "title": "The Verge -  All Posts",
        "htmlUrl": "http://www.theverge.com/"
      },
      "engagement": 15
    },
    {
      "id": "entryId2",
      "unread": true,
      "categories": [
        {
          "id": "user/c805fcbf-3acf-4302-a97e-d82f9d7c897f/category/tech",
          "label": "tech"
        }
      ],
      "tags": [
        {
          "id": "user/c805fcbf-3acf-4302-a97e-d82f9d7c897f/tag/inspiration",
          "label": "inspiration"
        }
      ],
      "title": "Senate rejects bipartisan gun control measure for background checks despite broad public support",
      "published": 1367539068016,
      "updated": 1367539068016,
      "crawled": 1367539068016,
      "alternate": [
        {
          "href": "http://www.theverge.com/2013/4/17/4236136/senate-rejects-gun-control-amendment",
          "type": "text/html"
        }
      ],
      "content": {
        "direction": "ltr",
        "content": "...html content..."
      },
      "author": "T.C. Sottek",
      "origin": {
        "streamId": "feed/http://www.theverge.com/rss/full.xml",
        "title": "The Verge -  All Posts",
        "htmlUrl": "http://www.theverge.com/"
      },
      "engagement": 39
    }
  ]
}

That is my solution but it doesn't work... what is my error? thanks

    try{
        //JSONArray elements = new JSONArray (response);
        JSONObject json=new JSONObject(response);
        JSONArray elements = json.getJSONArray("items");

        Log.d(TAG, "Elemenenti numero" +elements.length());

        // Getting Array of Contacts


        // looping through All Contacts
        for(int i = 0; i < elements.length(); i++){
            JSONObject c = elements.getJSONObject(i);



            // Storing each json item in variable

            String identifier = c.getString("id");
            String title = c.getString("title");
            String link = c.getString("originId");
            String data = c.getString("published");
            SimpleDateFormat  format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");  
            Date date=new Date();

            try {  
                date = format.parse(data);  
                System.out.println(date);  
            } catch (Exception e) {  
                e.printStackTrace();  
            }


            JSONObject summaryObj= c.getJSONObject("summary");
            String summary = summaryObj.getString("content");

            JSONObject contentObj= c.getJSONObject("content");
            String content = contentObj.getString("content");

            JSONObject sourceObj= c.getJSONObject("origin");
            String source = contentObj.getString("title");


            if (summary.length()==0 && content.length()!=0) summary=content;
            if (content.length()==0 && summary.length()!=0) content=summary;

            String image=this.getFirstImage(content);

            FeedItem toAdd=new FeedItem(identifier, title, link, date, null, summary, content, image, source);

            toAdd.toString();



        }


    }catch (JSONException e) {
        e.printStackTrace();
    }

Answer 1

JSONObject summaryObj= c.getJSONObject("summary");

There is no element called summary, you may try

if(c.has("summary")) {
    JSONObject summaryObj= c.getJSONObject("summary");
}

if that doesn't work, please post your stacktrace, (logcat)

Answer 2

You don't have any tag named "originID". but you are trying to get String from it.

Similarly,you don't have tag "summary" also but you are trying to get JSONObject from it.