谷歌的地方API为Android找到城市

Question

我已经看到教程(教程)在android.i中使用自动完成文本视图查找城市已完成所有指示但现在当我点击这个网址

它总是抛出一个异常说: java.net.UnknownHostException: Unable to resolve host "maps.googleapis.com": No address associated with hostname

但是当我通过浏览器点击时,同样的网址工作正常,我也得到了结果.

这是我的代码:

public class PlacesAutoCompleteAdapter extends ArrayAdapter< String > implements Filterable{
 private ArrayList<String> resultList;
 private static final String LOG_TAG = "ExampleApp";

 private static final String PLACES_API_BASE = "https://maps.googleapis.com/maps/api/place";
 private static final String TYPE_AUTOCOMPLETE = "/autocomplete";
 private static final String OUT_JSON = "/json";

 private static final String API_KEY = "I have generated the correct api key also";


public PlacesAutoCompleteAdapter(Context context, int textViewResourceId) {
    super(context, textViewResourceId);

}


@Override
public int getCount() {
    return resultList.size();
}

@Override
public String getItem(int index) {
    return resultList.get(index);
}

@Override
public Filter getFilter() {
    Filter filter = new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
              FilterResults filterResults = new FilterResults();
                if (constraint != null) {
                    // Retrieve the autocomplete results.
                    resultList = autocomplete(constraint.toString());

                    // Assign the data to the FilterResults
                    filterResults.values = resultList;
                    filterResults.count = resultList.size();
                }
                return filterResults;
        }

        @Override
        protected void publishResults(CharSequence constraint,
                FilterResults results) {
             if (results != null && results.count > 0) {
                    notifyDataSetChanged();
                }
                else {
                    notifyDataSetInvalidated();
                }
        }
    };
    return filter;
}

private ArrayList<String> autocomplete(String input) {
    ArrayList<String> resultList = null;

    HttpURLConnection conn = null;
    StringBuilder jsonResults = new StringBuilder();
    try {
        StringBuilder sb = new StringBuilder(PLACES_API_BASE + TYPE_AUTOCOMPLETE + OUT_JSON);
        sb.append("?sensor=false&key=" + API_KEY);
    //   sb.append("&components=country:in");
        sb.append("&input=" + URLEncoder.encode(input, "utf8"));
      // sb.append("&input=" + input);

       System.out.println("URL ---------------: "+sb.toString());
        URL url = new URL(sb.toString());
        conn = (HttpURLConnection) url.openConnection();
        InputStreamReader in = new InputStreamReader(conn.getInputStream());

        // Load the results into a StringBuilder
        int read;
        char[] buff = new char[1024];
        while ((read = in.read(buff)) != -1) {
            jsonResults.append(buff, 0, read);
        }
    } catch (MalformedURLException e) {
        Log.e(LOG_TAG, "Error processing Places API URL", e);
        return resultList;
    } catch (IOException e) {
        e.printStackTrace();
       // Log.e(LOG_TAG, "Error connecting to Places API", e);
        return resultList;
    } finally {
        if (conn != null) {
            conn.disconnect();
        }
    }

    try {
        // Create a JSON object hierarchy from the results
        JSONObject jsonObj = new JSONObject(jsonResults.toString());
        JSONArray predsJsonArray = jsonObj.getJSONArray("predictions");

        // Extract the Place descriptions from the results
        resultList = new ArrayList<String>(predsJsonArray.length());
        for (int i = 0; i < predsJsonArray.length(); i++) {
            resultList.add(predsJsonArray.getJSONObject(i).getString("description"));
        }
    } catch (JSONException e) {
        Log.e(LOG_TAG, "Cannot process JSON results", e);
    }

    return resultList;
}

}

---

哎呀!对不起大家.我发现解决方案是一个愚蠢的错误.我没有在清单中定义INTERNET权限.

Answer 1

请检查您的清单中是否添加了INTERNET权限.

<uses-permission android:name="android.permission.INTERNET"></uses-permission>