Search Places AutoComplete in Google Maps with Retrofit

Create Project

Create new project in Android Studio with steps as below:

Step 1: Input Project Name and Select Project Location

Step 2: Select SDK for Android App

Step 3: Select Default Activity for App

Step 4: Finish create project

Google Map API

Login to https://console.developers.google.com and create Places API key for testing. Create new xml file named google_maps_api.xml in res/values folder contains Places API key:

AIzaSyB9MxxJBmzLHdfsMEZSdV0vORR_MRwirPI

Add Library as Dependencies

Open build.gradle file in Gradle Scripts and add new library as below:

implementation 'com.google.android.gms:play-services-maps:15.0.1'
implementation 'com.google.android.gms:play-services-location:15.0.1'
implementation 'com.google.api-client:google-api-client:1.23.0'

implementation 'com.squareup.retrofit2:retrofit:2.3.0'
implementation 'com.google.code.gson:gson:2.6.2'
implementation 'com.squareup.retrofit2:converter-gson:2.1.0'
implementation 'com.squareup.okhttp3:logging-interceptor:3.4.1'
implementation 'com.squareup.okhttp3:okhttp:3.4.1'

Add Strings

Open res\values\strings.xml file and add new string as below:

<resources>
    <string name="app_name">Learn Android with Real Apps</string>
    <string name="input_your_place">Input your place...</string>
</resources>

Manifest Permissions

Open AndroidManifest.xml file in manifest folder, add permissions and google map api as below:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="android.demo.learnandroidwithrealapps">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key" />
    </application>

</manifest>

Create Entities

Create new package named entities. In this package, create new entities as below:

Term

Create new java class named Term.java as below:

package android.demo.entities;

import com.google.gson.annotations.SerializedName;

import java.io.Serializable;

public class Term implements Serializable {

    @SerializedName("offset")
    private int offset;

    @SerializedName("value")
    private String value;

    public int getOffset() {
        return this.offset;
    }

    public void setOffset(int offset) {
        this.offset = offset;
    }

    public String getValue() {
        return this.value;
    }

    public void setValue(String value) {
        this.value = value;
    }
}

MatchedSubstring

Create new java class named MatchedSubstring.java as below:

package android.demo.entities;

import com.google.gson.annotations.SerializedName;

import java.io.Serializable;

public class MatchedSubstring implements Serializable {

    @SerializedName("length")
    private int length;

    @SerializedName("offset")
    private int offset;

    public int getLength() {
        return this.length;
    }

    public void setLength(int length) {
        this.length = length;
    }

    public int getOffset() {
        return this.offset;
    }

    public void setOffset(int offset) {
        this.offset = offset;
    }
}

Prediction

Create new java class named Prediction.java as below:

package android.demo.entities;

import com.google.gson.annotations.SerializedName;
import java.io.Serializable;
import java.util.List;

public class Prediction implements Serializable {

    @SerializedName("description")
    private String description;

    @SerializedName("id")
    private String id;

    @SerializedName("matched_substrings")
    private List matchedSubstrings;

    @SerializedName("place_id")
    private String placeId;

    @SerializedName("reference")
    private String reference;

    @SerializedName("terms")
    private List<Term> terms;

    @SerializedName("types")
    private List<String> types;

    public String getDescription() {
        return this.description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getId() {
        return this.id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public List<MatchedSubstring> getMatchedSubstrings() {
        return this.matchedSubstrings;
    }

    public void setMatchedSubstrings(List<MatchedSubstring> matchedSubstrings) {
        this.matchedSubstrings = matchedSubstrings;
    }

    public String getPlaceId() {
        return this.placeId;
    }

    public void setPlaceId(String placeId) {
        this.placeId = placeId;
    }

    public String getReference() {
        return this.reference;
    }

    public void setReference(String reference) {
        this.reference = reference;
    }

    public List<Term> getTerms() {
        return this.terms;
    }

    public void setTerms(List<Term> terms) {
        this.terms = terms;
    }

    public List<String> getTypes() {
        return this.types;
    }

    public void setTypes(List<String> types) {
        this.types = types;
    }
}

Predictions

Create new java class named Predictions.java as below:

package android.demo.entities;

import com.google.gson.annotations.SerializedName;
import java.util.List;

public class Predictions {

    @SerializedName("status")
    private String status;

    @SerializedName("predictions")
    private List<Prediction> predictions;

    public String getStatus() {
        return this.status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public List<Prediction> getPredictions() {
        return this.predictions;
    }

    public void setPredictions(List<Prediction> predictions) {
        this.predictions = predictions;
    }
}

Custom Places Layout

Select res\layout folder. In this folder, create new layout named place_row_layout.xml as below:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/textViewName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="TextView"
        android:textSize="16sp"
        android:textStyle="bold" />

</LinearLayout>

Custom Adapter

Create new package named adapters. In this package, create new java class named PlacesAutoCompleteAdapter.java as below:

package android.demo.adapters;

import android.content.Context;
import android.demo.api.APIClient;
import android.demo.api.GoogleMapAPI;
import android.demo.entities.Prediction;
import android.demo.entities.Predictions;
import android.demo.learnandroidwithrealapps.R;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Filter;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class PlacesAutoCompleteAdapter extends ArrayAdapter<Prediction> {

    private Context context;
    private List<Prediction> predictions;

    public PlacesAutoCompleteAdapter(Context context, List<Prediction> predictions) {
        super(context, R.layout.place_row_layout, predictions);
        this.context = context;
        this.predictions = predictions;
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        View view = LayoutInflater.from(context).inflate(R.layout.place_row_layout, null);
        if (predictions != null && predictions.size() > 0) {
            Prediction prediction = predictions.get(position);
            TextView textViewName = view.findViewById(R.id.textViewName);
            textViewName.setText(prediction.getDescription());
        }
        return view;
    }

    @NonNull
    @Override
    public Filter getFilter() {
        return new PlacesAutoCompleteFilter(this, context);
    }

    private class PlacesAutoCompleteFilter extends Filter {

        private PlacesAutoCompleteAdapter placesAutoCompleteAdapter;
        private Context context;

        public PlacesAutoCompleteFilter(PlacesAutoCompleteAdapter placesAutoCompleteAdapter, Context context) {
            super();
            this.placesAutoCompleteAdapter = placesAutoCompleteAdapter;
            this.context = context;
        }

        @Override
        protected FilterResults performFiltering(CharSequence charSequence) {
            try {
                placesAutoCompleteAdapter.predictions.clear();
                FilterResults filterResults = new FilterResults();
                if (charSequence == null || charSequence.length() == 0) {
                    filterResults.values = new ArrayList<Prediction>();
                    filterResults.count = 0;
                } else {
                    GoogleMapAPI googleMapAPI = APIClient.getClient().create(GoogleMapAPI.class);
                    Predictions predictions = googleMapAPI.getPlacesAutoComplete(charSequence.toString(), "geocode", "en", context.getString(R.string.google_maps_key)).execute().body();
                    filterResults.values = predictions.getPredictions();
                    filterResults.count = predictions.getPredictions().size();
                }
                return filterResults;
            } catch (Exception e) {
                return null;
            }
        }

        @Override
        protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
            placesAutoCompleteAdapter.predictions.clear();
            placesAutoCompleteAdapter.predictions.addAll((List<Prediction>) filterResults.values);
            placesAutoCompleteAdapter.notifyDataSetChanged();
        }

        @Override
        public CharSequence convertResultToString(Object resultValue) {
            Prediction prediction = (Prediction) resultValue;
            return prediction.getDescription();
        }
    }

}

Retrofit API

Create new package named api. In this package, create new api as below:

APIClient

Create new java class named APIClient.java as below:

package android.demo.api;

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 Retrofit getClient() {

        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        OkHttpClient client = new OkHttpClient.Builder().addInterceptor(interceptor).build();
        retrofit = new Retrofit.Builder()
                                .baseUrl("https://maps.googleapis.com/maps/api/")
                                .addConverterFactory(GsonConverterFactory.create())
                                .client(client)
                                .build();
        return retrofit;
    }

}

GoogleMapAPI

Create new interface named GoogleMapAPI.java as below:

package android.demo.api;

import android.demo.entities.Predictions;

import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Query;

public interface GoogleMapAPI {

    @GET("place/autocomplete/json")
    public Call<Predictions> getPlacesAutoComplete(
            @Query("input") String input,
            @Query("types") String types,
            @Query("language") String language,
            @Query("key") String key
    );

}

Main Activity Layout

Open res\layout\activity_main.xml file and create layout as below:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <AutoCompleteTextView
        android:id="@+id/autoCompleteTextViewPlace"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/input_your_place" />

</LinearLayout>

Main Activity Class

Add code to MainActivity.java file in android.demo.learnandroidwithrealapps package as below:

package android.demo.learnandroidwithrealapps;

import android.demo.adapters.PlacesAutoCompleteAdapter;
import android.demo.entities.Prediction;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.AutoCompleteTextView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private AutoCompleteTextView autoCompleteTextViewPlace;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        autoCompleteTextViewPlace = findViewById(R.id.autoCompleteTextViewPlace);
        loadData();
    }

    private void loadData() {
        List<Prediction> predictions = new ArrayList<>();
        PlacesAutoCompleteAdapter placesAutoCompleteAdapter = new PlacesAutoCompleteAdapter(getApplicationContext(), predictions);
        autoCompleteTextViewPlace.setThreshold(1);
        autoCompleteTextViewPlace.setAdapter(placesAutoCompleteAdapter);
    }

}

Structure of Project

Run App

Load Main Activity

Input Keyword

Select A Result