java - JSON を解析してエラーメッセージを表示する

Question

トーストメッセージを追加し、WEBSERVICE がデータを返さないときにユーザーをメインアクティビティに戻し、詳細を説明できるようにしたいと考えています。ユーザーがクエリを検索すると、Web サービスは次のような JSON 文字列にデータを返します。

08-30 00:36:07.917: D/JSON String(1891): {
08-30 00:36:07.917: D/JSON String(1891): "all" :    {
08-30 00:36:07.917: D/JSON String(1891):    "count" : 25,
08-30 00:36:07.917: D/JSON String(1891):    "questions" : [     {   
08-30 00:36:07.917: D/JSON String(1891):            "Id" : "20100728112033AAb4hTA",
08-30 00:36:07.917: D/JSON String(1891):            "Subject" : "What is the oldest a bitch can more or less safely breed?",
08-30 00:36:07.917: D/JSON String(1891):            "Content" : "Don't worry I'm not going to breed - both my bitches are getting neutered in the next year, as is my dog! Just that me and a friend were talking about it after talking to the man who gave me Misty (my border collie) who said she could still breed at 7 - I thought the oldest was 5?\n",
08-30 00:36:07.917: D/JSON String(1891):            "Date" : "2010-07-28 18:20:33",
08-30 00:36:07.917: D/JSON String(1891):            "Timestamp" : "1280341233",
08-30 00:36:07.917: D/JSON String(1891):            "Link" : "http://answers.yahoo.com/question/?qid=20100728112033AAb4hTA",
08-30 00:36:07.917: D/JSON String(1891):            "Type" : "Answered",
08-30 00:36:07.917: D/JSON String(1891):            "CategoryId" : 396546021,
08-30 00:36:07.917: D/JSON String(1891):            "CategoryName" : "Dogs",
08-30 00:36:07.917: D/JSON String(1891):            "UserId" : "cP16Ctgxaa",
08-30 00:36:07.917: D/JSON String(1891):            "UserNick" : "Kiko",
08-30 00:36:07.917: D/JSON String(1891):            "UserPhotoURL" : "http://l.yimg.com/dg/users/1t1USxJpxAAEBQOGZjBMW0-5Wp_EG.medium.jpg",
08-30 00:36:07.917: D/JSON String(1891):            "NumAnswers" : 8,
08-30 00:36:07.917: D/JSON String(1891):            "NumComments" : 0,
08-30 00:36:07.917: D/JSON String(1891):            "ChosenAnswer" : "You just \"imagined\" that ,dear...not \"thought\". & your imagination is WRONG.\r\n\r\n9 or even 10,for a healthy TOP-PRODUCING bitc-h.\r\n\r\n\r\n\r\n*&* bitches are SPAYED & dogs are CASTRATED......big scary correct ADULT words.",
08-30 00:36:07.917: D/JSON String(1891):            "ChosenAnswererId" : "clN6YITvaa",
08-30 00:36:07.917: D/JSON String(1891):            "ChosenAnswererNick" : "Debunker",
08-30 00:36:07.917: D/JSON String(1891):            "ChosenAnswerTimestamp" : "1280317077",
08-30 00:36:07.917: D/JSON String(1891):            "ChosenAnswerAwardTimestamp" : "1280835336"
08-30 00:36:07.917: D/JSON String(1891):        },      {

そして、これが、このデータを解析して必要な特定のデータを取得する方法のコードです

protected String doInBackground(String... args) {

    try {
        Intent in = getIntent();
        String searchTerm = in.getStringExtra("TAG_SEARCH");
        String query = URLEncoder.encode(searchTerm, "utf-8");
        String URL = "http://example.com";
        JSONParsser jParser = new JSONParsser();
        JSONObject json = jParser.readJSONFeed(URL);
        try {

            JSONArray questions = json.getJSONObject("all").getJSONArray("questions");

            for(int i = 0; i < questions.length(); i++) {
                JSONObject question = questions.getJSONObject(i);


            String Subject = question.getString(TAG_QUESTION_SUBJECT);
            String ChosenAnswer = question.getString(TAG_QUESTION_CHOSENANSWER);
            String Content = question.getString(TAG_QUESTION_CONTENT);


            }


        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

        return TAG_QUESTION ;           

}

しかし、ユーザーがクエリを検索し、Web サービスが結果を返さない場合、つまり結果がないということは、Web サービスデータが持っていることを意味し、"count" : 0,このような JSON 文字列では次のようになります。

09-02 00:25:55.466: D/JSON String(882): {
09-02 00:25:55.466: D/JSON String(882): "all" : {
09-02 00:25:55.466: D/JSON String(882):     "count" : 0,
09-02 00:25:55.466: D/JSON String(882):     "questions" : [     ]
09-02 00:25:55.466: D/JSON String(882):     }
09-02 00:25:55.466: D/JSON String(882): }

これが発生した場合、トーストメッセージをポップアップしてユーザーをメインアクティビティに戻す必要がありますが、カウント 0 が返されたときにそのデータを解析する方法がわかりませんif。この場所にステートメントを追加する必要があることは既にわかっています。

        try {
            // if statement here
            JSONArray questions = json.getJSONObject("all").getJSONArray("questions");

            for(int i = 0; i < questions.length(); i++) {
                JSONObject question = questions.getJSONObject(i);


            String Subject = question.getString(TAG_QUESTION_SUBJECT);
            String ChosenAnswer = question.getString(TAG_QUESTION_CHOSENANSWER);
            String Content = question.getString(TAG_QUESTION_CONTENT);

"count" : 0,トーストメッセージを表示し、ユーザーをメインアクティビティに戻すには、解析方法を知る必要があります。ここで私のアイデアを見て、私の言いたいことを理解するのに問題がある場合はお知らせください. PS が何であるか疑問に思っている場合JSONParsser、それは私が Web サービスに接続するために使用するクラスであり、それsearchTermを渡しeditTextてエンコードするだけです。

@Override
protected void onPostExecute(String file_URL) { 

    if(file_URL.equals("0")) { 
        pDialog.dismiss();
        Toast.makeText(ListView.this, "No data found", Toast.LENGTH_SHORT).show();
        finish();    

}else{

        if (pDialog.isShowing()) pDialog.dismiss();
        ListAdapter adapter = new SimpleAdapter(getBaseContext(), questionList,
                R.layout.listelements,
                new String[] { TAG_QUESTION_SUBJECT }, new int[] {
                R.id.Subject,});

        setListAdapter(adapter);
}

アップデート

        protected JSONObject doInBackground(String... args) {  

            JSONObject json = new JSONObject();
            try {
                Intent in = getIntent();
                String searchTerm = in.getStringExtra("TAG_SEARCH");
                String query = URLEncoder.encode(searchTerm, "utf-8");
                String URL = "http://example.com";
                JSONParsser jParser = new JSONParsser();

                    json = jParser.readJSONFeed(URL);
                } catch (UnsupportedEncodingException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

                return json;           

            }

        @Override
        protected void onPostExecute(JSONObject json) { 

            int count = 0;
            try {
                count = json.getJSONObject("all").getInt("count");
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            if(count>0) { 
                pDialog.dismiss();
                Toast.makeText(ListView.this, "No data found", Toast.LENGTH_SHORT).show();
                finish();    

        }else{

                try {

                    JSONArray questions = json.getJSONObject("all").getJSONArray("questions");

                    for(int i = 0; i < questions.length(); i++) {
                        JSONObject question = questions.getJSONObject(i);


                    String Subject = question.getString(TAG_QUESTION_SUBJECT);
                    String ChosenAnswer = question.getString(TAG_QUESTION_CHOSENANSWER);
                    String Content = question.getString(TAG_QUESTION_CONTENT);

                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_QUESTION_SUBJECT, Subject);
                    map.put(TAG_QUESTION_CONTENT, Content);
                    map.put(TAG_QUESTION_CHOSENANSWER, ChosenAnswer);

                    questionList.add(map);

                    pDialog.dismiss();
                    ListAdapter adapter = new SimpleAdapter(getBaseContext(), questionList,
                                R.layout.listelements,
                                new String[] { TAG_QUESTION_SUBJECT }, new int[] {
                                R.id.Subject,});

                        setListAdapter(adapter);
                    }

                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

        }


    }

}

score 0 · Accepted Answer

こうすれば

protected String doInBackground(String... args) {

    try {
        Intent in = getIntent();
        String searchTerm = in.getStringExtra("TAG_SEARCH");
        String query = URLEncoder.encode(searchTerm, "utf-8");
        String URL = "http://example.com";
        JSONParsser jParser = new JSONParsser();
        JSONObject json = jParser.readJSONFeed(URL);
        try {
            if(Integer.parseInt(data.getJSONObject("all").getString("count"))<=0){ //UPDATE HERE
            return "0";
        }
            JSONArray questions = json.getJSONObject("all").getJSONArray("questions");

            for(int i = 0; i < questions.length(); i++) {
                JSONObject question = questions.getJSONObject(i);


            String Subject = question.getString(TAG_QUESTION_SUBJECT);
            String ChosenAnswer = question.getString(TAG_QUESTION_CHOSENANSWER);
            String Content = question.getString(TAG_QUESTION_CONTENT);


            }


        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

        return TAG_QUESTION ;           

}


@Override
            protected void onPostExecute(String result) {
                super.onPostExecute(result);
                if(result==null || result.equals("0")){
                     Toast.makeText(ActivityName.this, "No data found", Toast.LENGTH_SHORT).show();
                }

            }

java - JSON を解析してエラー メッセージを表示する

3 に答える 3

Related

Reference

java - JSON を解析してエラーメッセージを表示する