获取JSON数据时出错

Question

我正在开发一个Android应用程序。在这里，我想通过发送语言环境来获取国家名称意味着当地语言。任何人都可以告诉我问题出在哪里？我无法获取值并在微调器中显示。 我这样做了： -

 public class Main2Activity extends Activity {
    final Context context = this;
    public String readJSONFeed(String URL) {
        StringBuilder stringBuilder = new StringBuilder();
        HttpClient client = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(URL);
        try {
            HttpResponse response = client.execute(httpGet);
            StatusLine statusLine = response.getStatusLine();
            int statusCode = statusLine.getStatusCode();
            if (statusCode == 200) {
                HttpEntity entity = response.getEntity();
                InputStream content = entity.getContent();
                BufferedReader reader = new BufferedReader(
                        new InputStreamReader(content));
                String line;
                while ((line = reader.readLine()) != null) {
                    stringBuilder.append(line);
                }} else {
                Log.e("JSON", "Failed to download file");
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return stringBuilder.toString();
    }
    private class ReadJSONFeedTask extends AsyncTask<String, Void, String> {
        protected String doInBackground(String... urls) {
            return readJSONFeed(urls[0]);
        }
        protected void onPostExecute(String result) {
            Spinner mySpinner = (Spinner) findViewById(R.id.spinner1);
            try {
            BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
                String line;
             while((line=in.readLine())!=null){
                 JSONArray jsonArray = new JSONArray(line);
                for (int i = 0; i < jsonArray.length(); i++) {
                    JSONObject jsonObject = jsonArray.getJSONObject(i);
                    List<String> list = new ArrayList<String>();list.add(jsonObject.getString("name"));
                    mySpinner
                            .setAdapter(new ArrayAdapter<String>(
                                    Main2Activity.this,
                                    android.R.layout.simple_spinner_dropdown_item,
                                    list));
                }
             }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        String url = context.getResources().getConfiguration().locale
                .getLanguage();
        url = "http://Its my server address?locale=" + url.toUpperCase();
        Log.e("Web call", url);
                new ReadJSONFeedTask().execute(url);
    }
}

请帮帮我。

Answer 1

这里的问题是onPostExecute方法中的while循环。哪个阻止UI线程并将导致ANR。你是从System.in读什么的？ 根据逻辑，我了解所有国家名称在“结果”对象中可用。检查您在结果对象中获得的内容。 您正在向结果添加值但不使用它。这意味着doInBackground中的逻辑是无用的。我认为你试图通过从输入strem中读取行来从结果对象中分离行。您可以将每行存储在ArrayList中并使用它，而不是这样。以下是可能的解决方案。希望这有助于！

public class Main2Activity extends Activity {
        final Context context = this;

        public ArrayList<String> readJSONFeed(String URL) {
            // Add all lines to this list.
            ArrayList<String> data = new ArrayList<String>();
            HttpClient client = new DefaultHttpClient();
            HttpGet httpGet = new HttpGet(URL);
            try {
                HttpResponse response = client.execute(httpGet);
                StatusLine statusLine = response.getStatusLine();
                int statusCode = statusLine.getStatusCode();
                if (statusCode == 200) {
                    HttpEntity entity = response.getEntity();
                    InputStream content = entity.getContent();
                    BufferedReader reader = new BufferedReader(
                            new InputStreamReader(content));
                    String line;
                    while ((line = reader.readLine()) != null) {
                        data.add(line);
                    }
                } else {
                    Log.e("JSON", "Failed to download file");
                }
            } catch (ClientProtocolException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return data;
        }

        private class ReadJSONFeedTask extends
                AsyncTask<String, Void, ArrayList<String>> {
            protected ArrayList<String> doInBackground(String... urls) {
                return readJSONFeed(urls[0]);
            }

            protected void onPostExecute(ArrayList<String> result) {
                Spinner mySpinner = (Spinner) findViewById(R.id.spinner1);
                try {
                    // Parse each line and add "name" to this list.
                    List<String> nameList = new ArrayList<String>();
                    for (String line : result) {
                        JSONArray jsonArray = new JSONArray(line);
                        for (int i = 0; i < jsonArray.length(); i++) {
                            JSONObject jsonObject = jsonArray.getJSONObject(i);
                            nameList.add(jsonObject.getString("name"));
                        }
                    }
                    // Once complete traversing is done, set Adapter
                    mySpinner.setAdapter(new ArrayAdapter<String>(
                            Main2Activity.this,
                            android.R.layout.simple_spinner_dropdown_item,
                            nameList));

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

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            String url = context.getResources().getConfiguration().locale
                    .getLanguage();
            url = "http://Its my server address?locale=" + url.toUpperCase();
            Log.e("Web call", url);
            new ReadJSONFeedTask().execute(url);
        }
    }