Google 地点 API Web 服务示例

12 月 ago

科, 颖

10 minutes

在这个教程中，我们将使用Google Places API来寻找附近的地点。我们将开发一个应用程序，显示我们选择的附近地点以及与我们当前位置的大致距离和时间。我们将在应用程序中使用Google Places API Web Service和Distance Matrix API。

谷歌地点API

Google Places API Web Service允许我们根据一些参数（例如地点类型、当前是否有地点开放等）查询地点。附近搜索请求的HTTP URL格式如下：

https://maps.googleapis.com/maps/api/place/nearbysearch/output?parameters

推荐的输出格式是JSON，另一个选项是XML。所需的参数为：

rankby=distance或radius：如果其中一个被使用，另一个将不能被使用。

注意：rankby=distance需要指定以下参数之一：

关键词

可选参数包括opennow、pagetoken等等。更多细节请参考此页面。

谷歌距离矩阵 API

距离矩阵API用于计算两个或多个点之间的距离和时间。距离矩阵API的网址格式为：

https://maps.googleapis.com/maps/api/distancematrix/outputFormat?parameters

所需的参数是起点、终点和关键字。起点 – 这包含了计算旅行距离和时间的起始点。我们可以通过使用|分隔的多组坐标来传递更多的坐标。我们也可以传递地址/地点ID而不是坐标，服务会自动将其转换为经纬度坐标来计算距离和时间。示例代码：

https://maps.googleapis.com/maps/api/distancematrix/json?origins=Washington,DC&destinations=New+York+City,NY&key=YOUR_API_KEY

可选参数有:

避开：引入限制，例如过路费、室内等，以指定路线。

请访问此页面以获取更多详细信息。

启用API密钥

去 https://console.developers.google.com/ 并启用以下的API:

谷歌地点API适用于安卓系统

前往凭证并创建一个新的密钥。暂时将密钥限制设置为无。让我们开始这个教程的核心部分。我们将开发一个应用程序，允许我们根据当前位置搜索附近的地点，并在一个可滚动列表中显示这些地点。我们将根据在EditText中输入并以空格分隔的类型和名称关键字来搜索地点。例如：餐厅多米诺或咖啡馆素食

谷歌地点 API 示例项目结构

该项目包括一个单一的活动。一个适配器类为RecyclerView。一个模型类用于保存每个RecyclerView行的数据。两个POJO类用于将来自谷歌地点API和距离矩阵API的JSON响应转换为Gson。APIClient和ApiInterface用于使用Retrofit和端点。

Google Places API 示例代码

将以下依赖项添加到build.gradle文件中。

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'

‘io.nlopez.smartlocation:library:3.3.1’ 是一个定位追踪的第三方库，可以减少样板代码。下面是 APIClient.java 的代码。

package com.Olivia.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.Olivia.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是一个文件，用来存储来自Places API的响应。以下是它的代码。

package com.Olivia.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类保存了从Distance Matrix API返回的响应。以下是它的代码：

package com.Olivia.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;

        }
    }
}

以下是activity_main.xml文件的内容。

<?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.Olivia.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>

以下是MainActivity.java类的代码。

package com.Olivia.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<String> permissionsToRequest;
    private ArrayList<String> permissionsRejected = new ArrayList<>();
    private ArrayList<String> permissions = new ArrayList<>();
    private final static int ALL_PERMISSIONS_RESULT = 101;
    List<StoreModel> storeModels;
    ApiInterface apiService;

    String latLngString;
    LatLng latLng;

    RecyclerView recyclerView;
    EditText editText;
    Button button;
    List<PlacesPOJO.CustomA> 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
         */

        //Call<PlacesPOJO.Root> call = apiService.doPlaces(placeType, latLngString,"\""+ businessName +"\"", true, "distance", APIClient.GOOGLE_PLACE_API_KEY);

        Call<PlacesPOJO.Root> call = apiService.doPlaces(placeType, latLngString, businessName, true, "distance", APIClient.GOOGLE_PLACE_API_KEY);
        call.enqueue(new Callback<PlacesPOJO.Root>() {
            @Override
            public void onResponse(Call<PlacesPOJO.Root> call, Response<PlacesPOJO.Root> 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<PlacesPOJO.Root> call, Throwable t) {
                // Log error here since request failed
                call.cancel();
            }
        });


    }

    private ArrayList<String> findUnAskedPermissions(ArrayList<String> wanted) {
        ArrayList<String> 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<ResultDistanceMatrix> call = apiService.getDistance(APIClient.GOOGLE_PLACE_API_KEY, latLngString, info.geometry.locationA.lat + "," + info.geometry.locationA.lng);
        call.enqueue(new Callback<ResultDistanceMatrix>() {
            @Override
            public void onResponse(Call<ResultDistanceMatrix> call, Response<ResultDistanceMatrix> 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<ResultDistanceMatrix> call, Throwable t) {
                call.cancel();
            }
        });

    }
}

在上述代码中，我们首先通过使用SmartLocation库来询问运行时权限，然后获取当前位置。一旦我们完成了这一步，我们将EditText中的第一个单词作为类型传递给fetchStores()方法的type参数，并将第二个单词传递给name参数。该方法最终调用了Google Places API的Web服务。我们将搜索结果限制为10个。对于每个结果，我们使用fetchDistance()方法计算与商店之间的距离和时间。在对所有商店完成距离计算后，我们使用StoreModel.java数据类将数据填充到RecyclerViewAdapter.java类中。下面是StoreModel.java的代码：

package com.Olivia.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;
    }

}

每一行RecyclerView的布局都在下面的xml文件store_list_row.xml中给出。

<?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>

以下是RecyclerViewAdapter.java的代码。

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地点API示例应用程序的输出：注意：对于麦当劳和一些连锁餐厅，尤其是在印度地区，Places API不准确。一种解决方法是将参数名称的值放在双引号内，如下所示：

Call call = apiService.doPlaces(placeType, latLngString,"\""+ businessName +"\"", true, "distance", APIClient.GOOGLE_PLACE_API_KEY);

以下是根据我的位置输出的结果：本教程至此结束。你可以通过以下链接下载最终的Google Places API示例项目。

请下载Google Places API示例项目。