Google Map API

app.build.gradle

apply plugin: 'com.android.application'
apply plugin: 'com.cookpad.android.licensetools'

android {
    compileSdkVersion 26
    buildToolsVersion "26.0.0"
    defaultConfig {
        applicationId "com.example.shela.myapplication"
        minSdkVersion 23
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    productFlavors {
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:26.+'
    compile 'com.google.android.gms:play-services-maps:10.2.0'
    compile 'com.google.maps:google-maps-services:0.1.20'
    compile 'org.slf4j:slf4j-nop:1.7.25'
    testCompile 'junit:junit:4.12'
}

licenses.yml

- artifact: com.android.support:+:+
  name: Android Support Libraries
  copyrightHolder: The Android Open Source Project
  license: The Apache Software License, Version 2.0
  licenseUrl: http://www.apache.org/licenses/LICENSE-2.0.txt
- artifact: com.google.android.gms:+:+
  name: Google Play Services
  copyrightHolder: The Android Open Source Project
  license: Apache License, Version 2.0
- artifact: com.google.code.gson:gson:+
  name: Google Gson
  copyrightHolder: Google Inc.
  license: Apache License, Version 2.0
  url: https://github.com/google/gson
- artifact: com.google.maps:google-maps-services:+
  name: Java Client for Google Maps Services
  copyrightHolder: Google Inc.
  license: The Apache Software License, Version 2.0
  licenseUrl: http://www.apache.org/licenses/LICENSE-2.0.txt
  url: https://github.com/googlemaps/google-maps-services-java
- artifact: org.slf4j:+:+
  name: SLF4J
  copyrightHolder: QOS.ch
  license: MIT license
  licenseUrl: http://www.opensource.org/licenses/mit-license.php
  url: http://www.slf4j.org
- artifact: joda-time:joda-time:+
  name: Joda-Time
  copyrightHolder: Joda.org
  license: Apache License, Version 2.0
  licenseUrl: http://www.apache.org/licenses/LICENSE-2.0.txt
  url: http://www.joda.org/joda-time/
- artifact: com.squareup.okhttp:+:+
  name: OkHttp
  copyrightHolder: Square, Inc.
  license: Apache License, Version 2.0
  url: http://square.github.io/okhttp/
- artifact: com.squareup.okio:okio:+
  name: Okio
  copyrightHolder: Square, Inc.
  license: Apache License, Version 2.0
  url: https://github.com/square/okio

MapsActivity.java

package com.example.shela.myapplication;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.support.v4.content.ContextCompat;
import android.util.Log;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.PolylineOptions;
import com.google.maps.DirectionsApi;
import com.google.maps.GeoApiContext;
import com.google.maps.GeocodingApi;
import com.google.maps.errors.ApiException;
import com.google.maps.model.DirectionsResult;
import com.google.maps.model.GeocodingResult;
import com.google.maps.model.TravelMode;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.util.List;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        // 位置情報取得権限を要求する(不完全)
        // see http://qiita.com/akitaika_/items/27c4eaeea6960ac9bb0d
        // see http://wptrafficanalyzer.in/blog/showing-current-location-in-google-maps-using-api-v2-with-supportmapfragment/
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.ACCESS_FINE_LOCATION)) {
                //      この画面側で処理継続的な選択をされた場合は、別途 ActivityCompat.requestPermissions をするべし
                ActivityCompat.requestPermissions(this,
                        new String[]{ Manifest.permission.ACCESS_FINE_LOCATION }, 100);
            } else {
                // パーミッションの許可要求ダイアログを表示
                ActivityCompat.requestPermissions(this,
                        new String[]{ Manifest.permission.ACCESS_FINE_LOCATION }, 100);
            }
        } else {
            mMap.setMyLocationEnabled(true);
        }

        String httpProxy = System.getProperty("http.proxyHost");
        int httpPort = Integer.valueOf(System.getProperty("http.proxyPort"));
        GeoApiContext context = new GeoApiContext().setApiKey(getString(R.string.google_maps_key));
        context.setProxy(new Proxy(Proxy.Type.HTTP, new InetSocketAddress(httpProxy, httpPort)));
        try {
            // 出発点(名古屋駅)
            com.google.maps.model.LatLng departure = new com.google.maps.model.LatLng(35.17157, 136.884180);

            // 目的地(豊田市駅)の緯度経度を検索
            GeocodingResult[] arrivalResults = GeocodingApi.geocode(
                    context, "豊田市駅").language("ja").await();
            com.google.maps.model.LatLng arrival = arrivalResults[0].geometry.location;
            Log.d("tag", String.format("%s, %f, %f", arrivalResults[0].formattedAddress, arrival.lat, arrival.lng));

            // 出発点から目的地間のルート検索
            DirectionsResult directionResult = DirectionsApi.newRequest(context)
                    .origin(departure)
                    .destination(arrival)
                    .mode(TravelMode.DRIVING)
                    .language("ja")
                    .await();
            List<com.google.maps.model.LatLng> path = directionResult.routes[0].overviewPolyline.decodePath();
            // ルート表示
            PolylineOptions polylineOptions = new PolylineOptions();
            for (com.google.maps.model.LatLng latLng : path) {
                polylineOptions.add(new LatLng(latLng.lat, latLng.lng));
            }
            // 輪郭線
            mMap.addPolyline(polylineOptions.color(0xff000000).width(15));
            // 主線
            mMap.addPolyline(polylineOptions.color(0xff14a0ff).width(11));

            // 目的地マーカーを作成
            LatLng arrivalLatLng = new LatLng(path.get(path.size() - 1).lat, path.get(path.size() - 1).lng);
            mMap.addMarker(new MarkerOptions().position(arrivalLatLng));

            // 出発点をズーム表示
            LatLng departureLatLng = new LatLng(path.get(0).lat, path.get(0).lng);
            mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(departureLatLng, 15.0f));
        } catch (ApiException | IOException | InterruptedException e) {
            Log.e("tag", e.getMessage());
        }
    }
}

MyApplication.build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
        maven {
            url 'https://dl.bintray.com/cookpad-inc/maven/'
        }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'
        classpath 'info.attosoft.licensetools:license-tools-plugin:0.19.1_r1'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

https://github.com/googlemaps/google-maps-services-java/blob/master/src/main/java/com/google/maps/internal/OkHttpPendingResult.java

https://stackoverflow.com/a/34582595/4409409