下面是 Places API 搜索、自动完成和详细信息的更完整示例(包括 JSON 解析和一些异常处理)。它是为 Android 编写的,但可以轻松移植以供非 Android 使用(需要包含 org.json 库并使用不同的日志记录)。该类Place
是一个简单的值对象。
package com.example.google.places;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
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;
/**
* @author saxman
*/
public class PlacesService {
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 TYPE_DETAILS = "/details";
private static final String TYPE_SEARCH = "/search";
private static final String OUT_JSON = "/json";
// KEY!
private static final String API_KEY = "YOUR KEY";
public static ArrayList<Place> autocomplete(String input) {
ArrayList<Place> resultList = null;
HttpURLConnection conn = null;
StringBuilder jsonResults = new StringBuilder();
try {
StringBuilder sb = new StringBuilder(PLACES_API_BASE);
sb.append(TYPE_AUTOCOMPLETE);
sb.append(OUT_JSON);
sb.append("?sensor=false");
sb.append("&key=" + API_KEY);
sb.append("&input=" + URLEncoder.encode(input, "utf8"));
URL url = new URL(sb.toString());
conn = (HttpURLConnection) url.openConnection();
InputStreamReader in = new InputStreamReader(conn.getInputStream());
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<Place>(predsJsonArray.length());
for (int i = 0; i < predsJsonArray.length(); i++) {
Place place = new Place();
place.reference = predsJsonArray.getJSONObject(i).getString("reference");
place.name = predsJsonArray.getJSONObject(i).getString("description");
resultList.add(place);
}
} catch (JSONException e) {
Log.e(LOG_TAG, "Error processing JSON results", e);
}
return resultList;
}
public static ArrayList<Place> search(String keyword, double lat, double lng, int radius) {
ArrayList<Place> resultList = null;
HttpURLConnection conn = null;
StringBuilder jsonResults = new StringBuilder();
try {
StringBuilder sb = new StringBuilder(PLACES_API_BASE);
sb.append(TYPE_SEARCH);
sb.append(OUT_JSON);
sb.append("?sensor=false");
sb.append("&key=" + API_KEY);
sb.append("&keyword=" + URLEncoder.encode(keyword, "utf8"));
sb.append("&location=" + String.valueOf(lat) + "," + String.valueOf(lng));
sb.append("&radius=" + String.valueOf(radius));
URL url = new URL(sb.toString());
conn = (HttpURLConnection) url.openConnection();
InputStreamReader in = new InputStreamReader(conn.getInputStream());
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("results");
// Extract the Place descriptions from the results
resultList = new ArrayList<Place>(predsJsonArray.length());
for (int i = 0; i < predsJsonArray.length(); i++) {
Place place = new Place();
place.reference = predsJsonArray.getJSONObject(i).getString("reference");
place.name = predsJsonArray.getJSONObject(i).getString("name");
resultList.add(place);
}
} catch (JSONException e) {
Log.e(LOG_TAG, "Error processing JSON results", e);
}
return resultList;
}
public static Place details(String reference) {
HttpURLConnection conn = null;
StringBuilder jsonResults = new StringBuilder();
try {
StringBuilder sb = new StringBuilder(PLACES_API_BASE);
sb.append(TYPE_DETAILS);
sb.append(OUT_JSON);
sb.append("?sensor=false");
sb.append("&key=" + API_KEY);
sb.append("&reference=" + URLEncoder.encode(reference, "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 null;
} catch (IOException e) {
Log.e(LOG_TAG, "Error connecting to Places API", e);
return null;
} finally {
if (conn != null) {
conn.disconnect();
}
}
Place place = null;
try {
// Create a JSON object hierarchy from the results
JSONObject jsonObj = new JSONObject(jsonResults.toString()).getJSONObject("result");
place = new Place();
place.icon = jsonObj.getString("icon");
place.name = jsonObj.getString("name");
place.formatted_address = jsonObj.getString("formatted_address");
if (jsonObj.has("formatted_phone_number")) {
place.formatted_phone_number = jsonObj.getString("formatted_phone_number");
}
} catch (JSONException e) {
Log.e(LOG_TAG, "Error processing JSON results", e);
}
return place;
}
}