只能迭代数组或 java.lang.Iterable 的实例

Can only iterate over an array or an instance of java.lang.Iterable

提问by BoneStarr

Hi I keep getting this error, I'm trying to get tweets from twitter via JSON and cant seem to get rid of this on the "arr". Would I have to do a different for loop? I did try this but it keeps returning the same error.

嗨，我不断收到此错误，我正在尝试通过 JSON 从 twitter 获取推文，但似乎无法在“arr”上摆脱此错误。我必须做一个不同的 for 循环吗？我确实尝试过，但它一直返回相同的错误。

 public ArrayList<Tweet> getTweets(String searchTerm, int page) {
      String searchUrl = 
            "http://search.twitter.com/search.json?q=@" 
            + searchTerm + "&rpp=100&page=" + page;

      ArrayList<Tweet> tweets = 
            new ArrayList<Tweet>();

      HttpClient client = new  DefaultHttpClient();
      HttpGet get = new HttpGet(searchUrl);

      ResponseHandler<String> responseHandler = 
            new BasicResponseHandler();

      String responseBody = null;
      try {
        responseBody = client.execute(get, responseHandler);
      } catch(Exception ex) {
        ex.printStackTrace();
      }

      JSONObject jsonObject = null;
      JSONParser parser = new JSONParser();

      try {
        Object obj = parser.parse(responseBody);
        jsonObject=(JSONObject)obj;
      }catch(Exception ex){
        Log.v("TEST","Exception: " + ex.getMessage());
      }

      JSONArray<Object> arr = null;

      try {
        Object j = jsonObject.get("results");
        arr = (JSONArray)j;
      } catch(Exception ex){
        Log.v("TEST","Exception: " + ex.getMessage());
      }

      for(Object t : arr) {
        Tweet tweet = new Tweet(
          ((JSONObject)t).get("from_user").toString(),
          ((JSONObject)t).get("text").toString(),
          ((JSONObject)t).get("profile_image_url").toString()
        );
        tweets.add(tweet);
      }

      return tweets;
    }

Please help!!

请帮忙！！

采纳答案by Sebastien

As the exception says, you can only iterate with the for each loop on instances of java.lang.Iterable. JSONArrayis not one of them.

正如例外所说，您只能在 的实例上使用 for each 循环进行迭代java.lang.Iterable。JSONArray不是其中之一。

Use the "classic" for loop :

使用“经典” for 循环：

for(int i = 0; i < arr.length(); i++) {
   JSONObject t = (JSONObject) arr.get(i);
   Tweet tweet = new Tweet(
     t.get("from_user").toString(),
     t.get("text").toString(),
     t.get("profile_image_url").toString()
   );
   tweets.add(tweet);
 }

回答by Jeff Foster

JSONArraydoesn't implement Iterable. Use lengthand getto access the members within it (see here)

JSONArray不执行Iterable。使用length和get访问其中的成员（请参阅此处）

int count = arr.length();
for (int i=0;i<count;++i) {
  string s = arr.getString(i);
}