Google Place Autocomplete API调用入门

我正在使用Google place自动完成API调用。我从Google开发人员那边查找了参考。从那里我已经完成了一些代码，但是我没有得到结果，所以请帮助我找出我的错误……在此先感谢。

这是我的清单。

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.googleautocompleteapi"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

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

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.googleautocompleteapi.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

这是我的java文件

public class MainActivity extends Activity implements OnItemClickListener{

    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 = "AIzaSyD1kYc0zUlKO6i4KfV-ecefi2II6cs4eFM";

    static final HttpTransport HTTP_TRANSPORT = AndroidHttp.newCompatibleTransport();
    static final JsonFactory JSON_FACTORY = new JacksonFactory();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        AutoCompleteTextView autoCompView = (AutoCompleteTextView) findViewById(R.id.autocomplete);

        autoCompView.setText("Fisherman's Wharf, San Francisco, CA, United States");
        autoCompView.setAdapter(new PlacesAutoCompleteAdapter(this, android.R.layout.simple_dropdown_item_1line));
        autoCompView.setOnItemClickListener(this);

    }
    public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
        String str = (String) adapterView.getItemAtPosition(position);
        Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public static 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;
    }

    public class PlacesAutoCompleteAdapter extends ArrayAdapter<String> implements Filterable{
        private ArrayList<String> resultList;

        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;
        }

    }


}