通过json对象,Android和谷歌地图api从自动完成搜索功能获取位置信息

时间:2012-11-16 01:19:56

标签: java android google-maps dataadapter

我正在构建一个Android应用程序,用户可以按位置搜索并保存位置信息。搜索框具有自动完成功能,因此,当用户输入内容时,他实际上可以获得该框上的建议列表。 我在我的搜索框中实现了这一点。为此,我使用本教程实现了一个单独的数据适配器。但在这里我只能得到一个名单,但我也需要相应的纬度和经度。我怎么能得到它。这是位置视图文件中的代码,

LOC= (AutoCompleteTextView) findViewById(R.id.autoCompleteEditText1);
        Context ctx=this;
        LOC.setAdapter(new com.cuet.csezeroseven.dao.PlacesAutoCompleteAdapter(this,
                R.layout.list_item));

这是我使用的数据适配器,

import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.content.Context;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.Filter;
import android.widget.Filterable;



public class PlacesAutoCompleteAdapter extends ArrayAdapter<String> implements
        Filterable {
    private ArrayList<String> resultList;
    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";
    //do not change this key
    private static final String API_KEY = "my_key";
    private static final String TAG = "tag";

    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);
    }

    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:us");
            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(TAG, "Error processing Places API URL", e);
            return resultList;
        } catch (IOException e) {
            Log.e(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(TAG, "Cannot process JSON results", e);
        }

        return resultList;
    }

    @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;
    }
}

这完全是通过以下this教程编写的。

1 个答案:

答案 0 :(得分:0)

从这个Stackoverflow question开始,我想你必须使用第一个中的“参考”进行另一个查询。