Google Places API可以用于查找附近的地点。在本教程中，我们将开发一个应用程序，该应用程序显示我们选择的附近地点以及从我们当前位置到这些地点的大致距离和时间。我们将在应用程序中使用Google Places API Web服务和Distance Matrix API。
Google Places API
Google Places API Web服务允许我们根据一些参数查询地点，例如地点类型、地点是否正在营业等。附近搜索请求是以下形式的HTTP URL：
https://maps.googleapis.com/maps/api/place/nearbysearch/output?parameters
json是推荐的output，另一个是xml。必需的参数包括：
- key（API密钥）
- location
- rankby=distance或radius：如果使用其中一个，则不能使用另一个。
注意：rankby=distance需要指定以下参数之一：
- name：值可以是麦当劳、肯德基等。
- type：值可以是餐厅、咖啡厅等。
- keyword
可选参数包括opennow、pagetoken等。更多详情请参考this页面。
Google Distance Matrix API
Distance Matrix API 用于计算两个或多个点之间的距离和时间。 Distance Matrix API 的 URL 形式如下：
https://maps.googleapis.com/maps/api/distancematrix/outputFormat?parameters
所需参数包括 origins、destinations 和 key。 origins — 这包含了计算旅行距离和时间的起点。 我们可以通过管道符（|）分隔的多个坐标集传递。 我们也可以传递地址/地点 ID 而不是坐标，服务会自动将它们转换为经纬度坐标以计算距离和持续时间。 示例代码：
https://maps.googleapis.com/maps/api/distancematrix/json?origins=Washington,DC&destinations=New+York+City,NY&key=YOUR_API_KEY
可选参数包括：
- mode：这里期望的值包括
driving、bicycling、walking、transit - avoid：引入了限制条件到路线，比如
tolls、indoor等
更多详情请访问this页面。
启用 API 密钥
前往 https://console.developers.google.com/ 并启用以下 API：
- 谷歌地图距离矩阵API
- 谷歌地点API Web服务
- 谷歌地点API for Android
转到凭证并创建一个新密钥。现在将密钥限制设置为无。让我们来到教程的业务端。我们将开发一个应用程序，允许我们基于当前位置搜索附近的地点，并在RecyclerView中显示这些地点。我们将根据在EditText中输入并用空格分隔的类型和名称关键字来搜索地点。例如：餐厅 dominos或咖啡馆 素食
谷歌地点API示例项目结构
该项目由单个活动组成。RecyclerView的适配器类。一个模型类，用于保存每个RecyclerView行的数据。两个POJO类用于将JSON响应从Google Places API和Distance Matrix API转换为Gson。用于使用Retrofit和端点的APIClient和ApiInterface。
Google Places API示例代码
在build.gradle文件中添加以下依赖项
compile 'com.google.android.gms:play-services-location:10.2.1'
compile 'com.google.android.gms:play-services-places:10.2.1'
compile 'com.google.code.gson:gson:2.7'
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:converter-gson:2.1.0'
compile 'com.squareup.okhttp3:logging-interceptor:3.4.1'
compile 'com.squareup.okhttp3:okhttps:3.4.1'
compile 'io.nlopez.smartlocation:library:3.3.1'
compile 'com.android.support:cardview-v7:25.3.0'
compile 'com.android.support:recyclerview-v7:25.3.0'
compile 'io.nlopez.smartlocation:library:3.3.1'是一个定位跟踪的第三方库，可减少样板代码。以下是APIClient.java的代码：
package com.journaldev.nearbyplaces;
import java.util.concurrent.TimeUnit;
import okhttp3.OkHttpClient;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
public class APIClient {
private static Retrofit retrofit = null;
public static final String GOOGLE_PLACE_API_KEY = "ADD_YOUR_API_KEY_HERE";
public static String base_url = "https://maps.googleapis.com/maps/api/";
public static Retrofit getClient() {
HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
OkHttpClient client = new OkHttpClient.Builder().readTimeout(30, TimeUnit.SECONDS).writeTimeout(30, TimeUnit.SECONDS).addInterceptor(interceptor).build();
retrofit = null;
retrofit = new Retrofit.Builder()
.baseUrl(base_url)
.addConverterFactory(GsonConverterFactory.create())
.client(client)
.build();
return retrofit;
}
}
以下是ApiInterface.java的代码：
package com.journaldev.nearbyplaces;
import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Query;
public interface ApiInterface {
@GET("place/nearbysearch/json?")
Call<PlacesPOJO.Root> doPlaces(@Query(value = "type", encoded = true) String type, @Query(value = "location", encoded = true) String location, @Query(value = "name", encoded = true) String name, @Query(value = "opennow", encoded = true) boolean opennow, @Query(value = "rankby", encoded = true) String rankby, @Query(value = "key", encoded = true) String key);
@GET("distancematrix/json") // origins/destinations: LatLng as string
Call<ResultDistanceMatrix> getDistance(@Query("key") String key, @Query("origins") String origins, @Query("destinations") String destinations);
}
PlacesPOJO.java是保存来自Places API响应的文件。以下是其代码：
package com.journaldev.nearbyplaces;
import com.google.gson.annotations.SerializedName;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
public class PlacesPOJO {
public class Root implements Serializable {
@SerializedName("results")
public List<CustomA> customA = new ArrayList<>();
@SerializedName("status")
public String status;
}
public class CustomA implements Serializable {
@SerializedName("geometry")
public Geometry geometry;
@SerializedName("vicinity")
public String vicinity;
@SerializedName("name")
public String name;
}
public class Geometry implements Serializable{
@SerializedName("location")
public LocationA locationA;
}
public class LocationA implements Serializable {
@SerializedName("lat")
public String lat;
@SerializedName("lng")
public String lng;
}
}
ResultDistanceMatrix.java类保存来自Distance Matrix API的响应。以下是其代码：
package com.journaldev.nearbyplaces;
import com.google.gson.annotations.SerializedName;
import java.util.List;
public class ResultDistanceMatrix {
@SerializedName("status")
public String status;
@SerializedName("rows")
public List<InfoDistanceMatrix> rows;
public class InfoDistanceMatrix {
@SerializedName("elements")
public List elements;
public class DistanceElement {
@SerializedName("status")
public String status;
@SerializedName("duration")
public ValueItem duration;
@SerializedName("distance")
public ValueItem distance;
}
public class ValueItem {
@SerializedName("value")
public long value;
@SerializedName("text")
public String text;
}
}
}
activity_main.xml 文件如下所示：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="https://schemas.android.com/apk/res/android"
xmlns:tools="https://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#212121"
tools:context="com.journaldev.nearbyplaces.MainActivity">
<EditText
android:id="@+id/editText"
android:layout_width="match_parent"
android:textColor="@android:color/white"
android:textColorHint="@android:color/white"
android:text="restaurant mcdonalds"
android:hint="type name"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_toLeftOf="@+id/button"
android:layout_toStartOf="@+id/button" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:text="Search" />
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@+id/editText"
android:scrollbars="vertical" />
</RelativeLayout>
MainActivity.java 类代码如下：
package com.journaldev.nearbyplaces;
import android.annotation.TargetApi;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Build;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.google.android.gms.maps.model.LatLng;
import java.util.ArrayList;
import java.util.List;
import io.nlopez.smartlocation.OnLocationUpdatedListener;
import io.nlopez.smartlocation.SmartLocation;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import static android.Manifest.permission.ACCESS_COARSE_LOCATION;
import static android.Manifest.permission.ACCESS_FINE_LOCATION;
public class MainActivity extends AppCompatActivity {
private ArrayList permissionsToRequest;
private ArrayList permissionsRejected = new ArrayList<>();
private ArrayList permissions = new ArrayList<>();
private final static int ALL_PERMISSIONS_RESULT = 101;
List storeModels;
ApiInterface apiService;
String latLngString;
LatLng latLng;
RecyclerView recyclerView;
EditText editText;
Button button;
List results;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
permissions.add(ACCESS_FINE_LOCATION);
permissions.add(ACCESS_COARSE_LOCATION);
permissionsToRequest = findUnAskedPermissions(permissions);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (permissionsToRequest.size() > 0)
requestPermissions(permissionsToRequest.toArray(new String[permissionsToRequest.size()]), ALL_PERMISSIONS_RESULT);
else {
fetchLocation();
}
} else {
fetchLocation();
}
apiService = APIClient.getClient().create(ApiInterface.class);
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
recyclerView.setNestedScrollingEnabled(false);
recyclerView.setHasFixedSize(true);
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
editText = (EditText) findViewById(R.id.editText);
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String s = editText.getText().toString().trim();
String[] split = s.split("\\s+");
if (split.length != 2) {
Toast.makeText(getApplicationContext(), "Please enter text in the required format", Toast.LENGTH_SHORT).show();
} else
fetchStores(split[0], split[1]);
}
});
}
private void fetchStores(String placeType, String businessName) {
/**
* For Locations In India McDonalds stores aren't returned accurately
*/
// 调用 call = apiService.doPlaces(placeType, latLngString,"\""+ businessName +"\"", true, "distance", APIClient.GOOGLE_PLACE_API_KEY);
Call call = apiService.doPlaces(placeType, latLngString, businessName, true, "distance", APIClient.GOOGLE_PLACE_API_KEY);
call.enqueue(new Callback() {
@Override
public void onResponse(Call call, Response response) {
PlacesPOJO.Root root = response.body();
if (response.isSuccessful()) {
if (root.status.equals("OK")) {
results = root.customA;
storeModels = new ArrayList<>();
for (int i = 0; i < results.size(); i++) {
if (i == 10)
break;
PlacesPOJO.CustomA info = results.get(i);
fetchDistance(info);
}
} else {
Toast.makeText(getApplicationContext(), "No matches found near you", Toast.LENGTH_SHORT).show();
}
} else if (response.code() != 200) {
Toast.makeText(getApplicationContext(), "Error " + response.code() + " found.", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onFailure(Call call, Throwable t) {
// 在这里记录错误，因为请求失败
call.cancel();
}
});
}
private ArrayList findUnAskedPermissions(ArrayList wanted) {
ArrayList result = new ArrayList<>();
for (String perm : wanted) {
if (!hasPermission(perm)) {
result.add(perm);
}
}
return result;
}
private boolean hasPermission(String permission) {
if (canMakeSmores()) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
return (checkSelfPermission(permission) == PackageManager.PERMISSION_GRANTED);
}
}
return true;
}
private boolean canMakeSmores() {
return (Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP_MR1);
}
@TargetApi(Build.VERSION_CODES.M)
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case ALL_PERMISSIONS_RESULT:
for (String perms : permissionsToRequest) {
if (!hasPermission(perms)) {
permissionsRejected.add(perms);
}
}
if (permissionsRejected.size() > 0) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (shouldShowRequestPermissionRationale(permissionsRejected.get(0))) {
showMessageOKCancel("These permissions are mandatory for the application. Please allow access.",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(permissionsRejected.toArray(new String[permissionsRejected.size()]), ALL_PERMISSIONS_RESULT);
}
}
});
return;
}
}
} else {
fetchLocation();
}
break;
}
}
private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) {
new AlertDialog.Builder(MainActivity.this)
.setMessage(message)
.setPositiveButton("OK", okListener)
.setNegativeButton("Cancel", null)
.create()
.show();
}
private void fetchLocation() {
SmartLocation.with(this).location()
.oneFix()
.start(new OnLocationUpdatedListener() {
@Override
public void onLocationUpdated(Location location) {
latLngString = location.getLatitude() + "," + location.getLongitude();
latLng = new LatLng(location.getLatitude(), location.getLongitude());
}
});
}
private void fetchDistance(final PlacesPOJO.CustomA info) {
Call call = apiService.getDistance(APIClient.GOOGLE_PLACE_API_KEY, latLngString, info.geometry.locationA.lat + "," + info.geometry.locationA.lng);
call.enqueue(new Callback() {
@Override
public void onResponse(Call call, Response response) {
ResultDistanceMatrix resultDistance = response.body();
if ("OK".equalsIgnoreCase(resultDistance.status)) {
ResultDistanceMatrix.InfoDistanceMatrix infoDistanceMatrix = resultDistance.rows.get(0);
ResultDistanceMatrix.InfoDistanceMatrix.DistanceElement distanceElement = infoDistanceMatrix.elements.get(0);
if ("OK".equalsIgnoreCase(distanceElement.status)) {
ResultDistanceMatrix.InfoDistanceMatrix.ValueItem itemDuration = distanceElement.duration;
ResultDistanceMatrix.InfoDistanceMatrix.ValueItem itemDistance = distanceElement.distance;
String totalDistance = String.valueOf(itemDistance.text);
String totalDuration = String.valueOf(itemDuration.text);
storeModels.add(new StoreModel(info.name, info.vicinity, totalDistance, totalDuration));
if (storeModels.size() == 10 || storeModels.size() == results.size()) {
RecyclerViewAdapter adapterStores = new RecyclerViewAdapter(results, storeModels);
recyclerView.setAdapter(adapterStores);
}
}
}
}
@Override
public void onFailure(Call call, Throwable t) {
call.cancel();
}
});
}
}
在上述代码中，我们首先请求运行时权限，然后使用 SmartLocation 库获取当前位置。一旦我们完成了这一步，我们将编辑框中的第一个单词作为类型传递，并将第二个单词作为fetchStores() 方法中的名称参数，该方法最终调用 Google Places API web 服务。我们将搜索结果限制为10个。对于每个结果，我们在fetchDistance() 方法中计算与商店的距离和时间。一旦对所有商店完成了此操作，我们将使用RecyclerViewAdapter.java 类在StoreModel.java 数据类中填充数据。StoreModel.java 代码如下所示：
package com.journaldev.nearbyplaces;
public class StoreModel {
public String name, address, distance, duration;
public StoreModel(String name, String address, String distance, String duration) {
this.name = name;
this.address = address;
this.distance = distance;
this.duration = duration;
}
}
RecyclerView 的每一行的布局如下所示：store_list_row.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="https://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="@dimen/activity_horizontal_margin"
android:orientation="vertical">
<android.support.v7.widget.CardView xmlns:card_view="https://schemas.android.com/apk/res-auto"
android:id="@+id/card_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
card_view:cardCornerRadius="0dp"
card_view:cardElevation="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="5dp">
<TextView
android:id="@+id/txtStoreName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingBottom="5dp"
android:textColor="#212121" />
<TextView
android:id="@+id/txtStoreAddr"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingBottom="5dp"
android:textColor="#212121" />
<TextView
android:id="@+id/txtStoreDist"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingBottom="5dp" />
</LinearLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
RecyclerViewAdapter.java 代码如下所示。
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyViewHolder> {
private List<PlacesPOJO.CustomA> stLstStores;
private List<StoreModel> models;
public RecyclerViewAdapter(List<PlacesPOJO.CustomA> stores, List<StoreModel> storeModels) {
stLstStores = stores;
models = storeModels;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
final View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.store_list_row, parent, false);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.setData(stLstStores.get(holder.getAdapterPosition()), holder, models.get(holder.getAdapterPosition()));
}
@Override
public int getItemCount() {
return Math.min(5, stLstStores.size());
}
public class MyViewHolder extends RecyclerView.ViewHolder {
TextView txtStoreName;
TextView txtStoreAddr;
TextView txtStoreDist;
StoreModel model;
public MyViewHolder(View itemView) {
super(itemView);
this.txtStoreDist = (TextView) itemView.findViewById(R.id.txtStoreDist);
this.txtStoreName = (TextView) itemView.findViewById(R.id.txtStoreName);
this.txtStoreAddr = (TextView) itemView.findViewById(R.id.txtStoreAddr);
}
public void setData(PlacesPOJO.CustomA info, MyViewHolder holder, StoreModel storeModel) {
this.model = storeModel;
holder.txtStoreDist.setText(model.distance + "\n" + model.duration);
holder.txtStoreName.setText(info.name);
holder.txtStoreAddr.setText(info.vicinity);
}
}
}
以下是Google Places API示例应用程序的输出结果：
注意：Places API对于麦当劳和一些连锁餐饮店的准确性不高，尤其是印度地区的位置。一种解决方法是在参数name中传递值，例如：
Call call = apiService.doPlaces(placeType, latLngString,"\""+ businessName +"\"", true, "distance", APIClient.GOOGLE_PLACE_API_KEY);
我的位置的输出如下：
这就结束了本教程。您可以从以下链接下载最终的Google Places API示例项目：
Source:
https://www.digitalocean.com/community/tutorials/google-places-api