Android 显示附近位置和位置详细信息程序引发空指针异常

我已经编写了一个程序来查找附近的地点，这些地点用一个标记完美地显示出来，而且当我点击标记时，信息窗口会显示详细信息，但我想在新活动中显示信息窗口上出现的地点详细信息，在这个参考的帮助下，我正确地遵循了这些步骤。 参考链接：

但是我在PlaceDetailsActivity类的onPostExecute方法的第一行上得到了一个空指针异常，这是我在其中显示infowindow详细信息的新活动。我想不出是什么问题，需要帮助吗

同时在此处发布代码：

PlaceDetailsActivity:在onPostEcecute的第一行上获取错误

public class PlaceDetailsActivity extends Activity {

WebView mWvPlaceDetails;

private static final String BROWSER_API_KEY = "AIzaSyDcFG73vwdcSrEDdOSVWavV71eqeGIwjXY";

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_place_details);

    // Getting reference to WebView ( wv_place_details ) of the layout
    // activity_place_details
    mWvPlaceDetails = (WebView) findViewById(R.id.wv_place_details);

    mWvPlaceDetails.getSettings().setUseWideViewPort(false);

    // Getting place reference from the map
    String reference = getIntent().getStringExtra("reference");

    StringBuilder sb = new StringBuilder(
            "https://maps.googleapis.com/maps/api/place/details/json?");
    sb.append("reference=" + reference);
    sb.append("&sensor=true");
    sb.append("&key=" + BROWSER_API_KEY);

    // Creating a new non-ui thread task to download Google place details
    PlacesTask placesTask = new PlacesTask();

    // Invokes the "doInBackground()" method of the class PlaceTask
    placesTask.execute(sb.toString());

};

/** A method to download json data from url */
private String downloadUrl(String strUrl) throws IOException {
    String data = "";
    InputStream iStream = null;
    HttpURLConnection urlConnection = null;
    try {
        URL url = new URL(strUrl);

        // Creating an http connection to communicate with url
        urlConnection = (HttpURLConnection) url.openConnection();

        // Connecting to url
        urlConnection.connect();

        // Reading data from url
        iStream = urlConnection.getInputStream();

        BufferedReader br = new BufferedReader(new InputStreamReader(
                iStream));

        StringBuffer sb = new StringBuffer();

        String line = "";
        while ((line = br.readLine()) != null) {
            sb.append(line);
        }

        data = sb.toString();
        br.close();

    } catch (Exception e) {
        Log.d("Exception while downloading url", e.toString());
    } finally {
        iStream.close();
        urlConnection.disconnect();
    }
    return data;
}

/** A class, to download Google Place Details */
private class PlacesTask extends AsyncTask<String, Integer, String> {

    String data = null;

    // Invoked by execute() method of this object
    @Override
    protected String doInBackground(String... url) {
        try {
            data = downloadUrl(url[0]);
        } catch (Exception e) {
            Log.d("Background Task", e.toString());
        }
        return data;
    }

    // Executed after the complete execution of doInBackground() method
    @Override
    protected void onPostExecute(String result) {
        ParserTask parserTask = new ParserTask();

        // Start parsing the Google place details in JSON format
        // Invokes the "doInBackground()" method of the class ParseTask
        parserTask.execute(result);
    }
}

/** A class to parse the Google Place Details in JSON format */
private class ParserTask extends
        AsyncTask<String, Integer, HashMap<String, String>> {

    JSONObject jObject;

    // Invoked by execute() method of this object
    @Override
    protected HashMap<String, String> doInBackground(String... jsonData) {

        HashMap<String, String> hPlaceDetails = null;
        PlaceDetailsJSONParser placeDetailsJsonParser = new PlaceDetailsJSONParser();

        try {
            jObject = new JSONObject(jsonData[0]);

            // Start parsing Google place details in JSON format
            hPlaceDetails = placeDetailsJsonParser.parse(jObject);

        } catch (Exception e) {
            Log.d("Exception", e.toString());
        }
        return hPlaceDetails;
    }

    // Executed after the complete execution of doInBackground() method
    @Override
    protected void onPostExecute(HashMap<String, String> hPlaceDetails) {

        String name = hPlaceDetails.get("name");
        String icon = hPlaceDetails.get("icon");
        String vicinity = hPlaceDetails.get("vicinity");
        String lat = hPlaceDetails.get("lat");
        String lng = hPlaceDetails.get("lng");
        String formatted_address = hPlaceDetails.get("formatted_address");
        String formatted_phone_number = hPlaceDetails
                .get("formatted_phone_number");
        String website = hPlaceDetails.get("website");
        String rating = hPlaceDetails.get("rating");
        String international_phone_number = hPlaceDetails
                .get("international_phone_number");
        String url = hPlaceDetails.get("url");

        String mimeType = "text/html";
        String encoding = "utf-8";

        String data = "<html>" + "<body><img style='float:left' src="
                + icon + " /><h1><center>" + name + "</center></h1>"
                + "<br style='clear:both' />" + "<hr />" + "<p>Vicinity : "
                + vicinity + "</p>" + "<p>Location : " + lat + "," + lng
                + "</p>" + "<p>Address : " + formatted_address + "</p>"
                + "<p>Phone : " + formatted_phone_number + "</p>"
                + "<p>Website : " + website + "</p>" + "<p>Rating : "
                + rating + "</p>" + "<p>International Phone : "
                + international_phone_number + "</p>"
                + "<p>URL : <a href='" + url + "'>" + url + "</p>"
                + "</body></html>";

        // Setting the data in WebView
        mWvPlaceDetails.loadDataWithBaseURL("", data, mimeType, encoding,
                "");
    }
}

---

请在PlaceDetailsActivity.java中发布您的日志行号：148是什么？？？String name=hplacetails.get（“name”）；检查onPostExecute中的

hPlaceDetails.get（“name”）

是否为空。还要检查日志中是否有任何名为Exception的错误

public class PlaceDetailsJSONParser {

/** Receives a JSONObject and returns a list */
public HashMap<String, String> parse(JSONObject jObject) {

    JSONObject jPlaceDetails = null;
    try {
        /** Retrieves all the elements in the 'places' array */
        jPlaceDetails = jObject.getJSONObject("result");
    } catch (JSONException e) {
        e.printStackTrace();
    }
    /**
     * Invoking getPlaces with the array of json object where each json
     * object represent a place
     */
    return getPlaceDetails(jPlaceDetails);
}

/** Parsing the Place Details Object object */
private HashMap<String, String> getPlaceDetails(JSONObject jPlaceDetails) {

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

    String name = "-NA-";
    String icon = "-NA-";
    String vicinity = "-NA-";
    String latitude = "";
    String longitude = "";
    String formatted_address = "-NA-";
    String formatted_phone_number = "-NA-";
    String website = "-NA-";
    String rating = "-NA-";
    String international_phone_number = "-NA-";
    String url = "-NA-";

    try {
        // Extracting Place name, if available
        if (!jPlaceDetails.isNull("name")) {
            name = jPlaceDetails.getString("name");
        }

        // Extracting Icon, if available
        if (!jPlaceDetails.isNull("icon")) {
            icon = jPlaceDetails.getString("icon");
        }

        // Extracting Place Vicinity, if available
        if (!jPlaceDetails.isNull("vicinity")) {
            vicinity = jPlaceDetails.getString("vicinity");
        }

        // Extracting Place formatted_address, if available
        if (!jPlaceDetails.isNull("formatted_address")) {
            formatted_address = jPlaceDetails
                    .getString("formatted_address");
        }

        // Extracting Place formatted_phone, if available
        if (!jPlaceDetails.isNull("formatted_phone_number")) {
            formatted_phone_number = jPlaceDetails
                    .getString("formatted_phone_number");
        }

        // Extracting website, if available
        if (!jPlaceDetails.isNull("website")) {
            website = jPlaceDetails.getString("website");
        }

        // Extracting rating, if available
        if (!jPlaceDetails.isNull("rating")) {
            rating = jPlaceDetails.getString("rating");
        }

        // Extracting rating, if available
        if (!jPlaceDetails.isNull("international_phone_number")) {
            international_phone_number = jPlaceDetails
                    .getString("international_phone_number");
        }

        // Extracting url, if available
        if (!jPlaceDetails.isNull("url")) {
            url = jPlaceDetails.getString("url");
        }

        latitude = jPlaceDetails.getJSONObject("geometry")
                .getJSONObject("location").getString("lat");
        longitude = jPlaceDetails.getJSONObject("geometry")
                .getJSONObject("location").getString("lng");

        hPlaceDetails.put("name", name);
        hPlaceDetails.put("icon", icon);
        hPlaceDetails.put("vicinity", vicinity);
        hPlaceDetails.put("lat", latitude);
        hPlaceDetails.put("lng", longitude);
        hPlaceDetails.put("formatted_address", formatted_address);
        hPlaceDetails.put("formatted_phone_number", formatted_phone_number);
        hPlaceDetails.put("website", website);
        hPlaceDetails.put("rating", rating);
        hPlaceDetails.put("international_phone_number",
                international_phone_number);
        hPlaceDetails.put("url", url);

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return hPlaceDetails;
}

12-26 22:17:47.896: E/AndroidRuntime(9806): FATAL EXCEPTION: main
12-26 22:17:47.896: E/AndroidRuntime(9806): java.lang.NullPointerException
12-26 22:17:47.896: E/AndroidRuntime(9806):     at com.android.d_governance.PlaceDetailsActivity$ParserTask.onPostExecute(PlaceDetailsActivity.java:148)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at com.android.d_governance.PlaceDetailsActivity$ParserTask.onPostExecute(PlaceDetailsActivity.java:1)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at android.os.AsyncTask.finish(AsyncTask.java:631)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at android.os.AsyncTask.access$600(AsyncTask.java:177)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at android.os.Handler.dispatchMessage(Handler.java:99)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at android.os.Looper.loop(Looper.java:158)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at android.app.ActivityThread.main(ActivityThread.java:5751)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at java.lang.reflect.Method.invokeNative(Native Method)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at java.lang.reflect.Method.invoke(Method.java:511)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1083)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:850)
12-26 22:17:47.896: E/AndroidRuntime(9806):     at dalvik.system.NativeStart.main(Native Method)