如何在 Android 中实现 Google Places API？

Question

我正在尝试开发一个应用程序，该应用程序允许用户通过实现 Google Places API 来定位附近的机构。但是，没有任何关于如何完成此操作的综合教程/示例。我已经能够拼凑一些代码，但我仍然不知道如何解析结果并随后将它们显示在我的叠加层上。非常感谢任何帮助。

Answer 1

您是否知道更具体的问题出在哪里（解析结果或放置图钉）？您看到了哪些类型的错误？

关于解析 Places API 结果，有一个教程： https://developers.google.com/academy/apis/maps/places/autocomplete-android

本教程中的以下代码应该可以帮助您开始解析结果。为自动完成和搜索 API 返回的 JSON 相似，但不一样。请务必遵循https://developers.google.com/places/documentation/#PlaceSearchResults 的格式。

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 = "YOUR_API_KEY";

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:uk");
        sb.append("&input=" + URLEncoder.encode(input, "utf8"));

        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) {
        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;
}