This is a helper class for generating a URL to grab a static map from Google's Static Map API.

StaticMapUrl Android

import android.location.Location;
import android.support.annotation.NonNull;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

/**
 * Created by Daniel Carmo on 2016-12-30.
 * Copyright © 2016 DMCApps Inc. All rights reserved.
 *
 * This is a helper class for generating a URL to grab a static map from Google's Static Map API.
 */

public final class StaticMapUrlBuilder {

    public enum Color {
        BLACK("black"),
        BROWN("brown"),
        GREEN("green"),
        PURPLE("purple"),
        YELLOW("yellow"),
        BLUE("blue"),
        GRAY("gray"),
        ORANGE("orange"),
        RED("red"),
        WHITE("white");

        private String color;
        Color(String color) {
            this.color = color;
        }

        String toApiString() {
            return color;
        }
    }

    private static final String TAG = StaticMapUrlBuilder.class.getSimpleName();

    private static final String BASE_URL = "https://maps.googleapis.com/maps/api/staticmap?size=%dx%d&key=%s";

    private final String apiKey;

    private final int width;
    private final int height;
    private Integer scale = null;

    private String centerLocation = null;
    private Double centerLat = null;
    private Double centerLng = null;

    private Integer zoom = null;
    private List<MarkerLocation> markerLocations;

    private List<Path> paths;

    public static class MarkerLocation {

        public enum MarkerSize {
            TINY("tiny"),
            MID("mid"),
            SMALL("small");

            private String color;
            MarkerSize(String color) {
                this.color = color;
            }

            String toApiString() {
                return color;
            }
        }

        Color color;
        MarkerSize size;
        Character label;
        String location;
        Double lat;
        Double lng;

        private MarkerLocation(Color color, MarkerSize size) {
            this.color = color;
            this.size = size;
        }

        public MarkerLocation(Color color, MarkerSize size, @NonNull String location) {
            this(color, size);
            this.location = location;
        }

        public MarkerLocation(Color color, MarkerSize size, @NonNull String location, Character label) {
            this(color, size, location);
            this.label = label;
        }

        public MarkerLocation(Color color, MarkerSize size, Location location) {
            this(color, size, location.getLatitude(), location.getLongitude(), null);
        }

        public MarkerLocation(Color color, MarkerSize size, Location location, Character label) {
            this(color, size, location.getLatitude(), location.getLongitude(), label);
        }

        public MarkerLocation(Color color, MarkerSize size, double lat, double lng) {
            this(color, size, lat, lng, null);
        }

        public MarkerLocation(Color color, MarkerSize size, double lat, double lng, Character label) {
            this(color, size);
            this.lat = lat;
            this.lng = lng;
            this.label = label;
        }

        @Override
        public String toString() {
            StringBuilder sb = new StringBuilder();

            sb.append(String.format(Locale.ENGLISH, "color:%s", color.toApiString()));
            sb.append(String.format(Locale.ENGLISH, "%%7Csize:%s", size.toApiString()));

            if (label != null) {
                sb.append(String.format(Locale.ENGLISH, "%%7Clabel:%s", label.toString().toUpperCase()));
            }

            if (lat != null && lng != null) {
                sb.append(String.format(Locale.ENGLISH, "%%7C%f,%f", lat, lng));
            }
            else if (location != null) {
                sb.append(String.format(Locale.ENGLISH, "%%7C%s", location.replace(" ", "+")));
            }

            return sb.toString();
        }
    }

    public static class Path {
        private Color color;
        private Integer weight;
        private List<Location> pointsOnPath;
        private String encodedPoints;

        public Path(Color color, Integer weight, List<Location> pointsOnPath) {
            this.color = color;
            this.weight = weight;
            this.pointsOnPath = pointsOnPath;
        }

        public Path(Color color, Integer weight, String encodedPoints) {
            this.color = color;
            this.weight = weight;
            this.encodedPoints = encodedPoints;
        }

        @Override
        public String toString() {
            StringBuilder sb = new StringBuilder();

            if (weight != null) {
                sb.append(String.format(Locale.ENGLISH, "weight:%d%%7C", weight));
            }

            sb.append(String.format(Locale.ENGLISH, "color:%s", color.toApiString()));

            if (pointsOnPath != null) {
                for (Location location : pointsOnPath) {
                    sb.append("%7C");
                    sb.append(String.format(Locale.ENGLISH, "%f,%f", location.getLatitude(), location.getLongitude()));
                }
            }

            if (encodedPoints != null && !encodedPoints.isEmpty()) {
                sb.append(String.format(Locale.ENGLISH, "%%7Cenc:%s", encodedPoints));
            }

            return sb.toString();
        }
    }

    public StaticMapUrlBuilder(int width, int height, @NonNull String apiKey) {
        this.width = width;
        this.height = height;
        this.apiKey = apiKey;
    }

    public StaticMapUrlBuilder center(@NonNull String location) {
        this.centerLocation = location;
        return this;
    }

    public StaticMapUrlBuilder center(double lat, double lng) {
        this.centerLat = lat;
        this.centerLng = lng;
        return this;
    }

    public StaticMapUrlBuilder scale(int scale) {
        this.scale = Math.min(scale, 2);
        return this;
    }

    public StaticMapUrlBuilder zoom(int zoom) {
        this.zoom = Math.min(zoom, 20);
        return this;
    }

    public StaticMapUrlBuilder addMarkerLocation(@NonNull MarkerLocation markerLocation) {
        if (markerLocations == null) {
            markerLocations = new ArrayList<>();
        }
        markerLocations.add(markerLocation);

        return this;
    }

    public StaticMapUrlBuilder addPath(@NonNull Path path) {
        if (paths == null) {
            paths = new ArrayList<>();
        }
        paths.add(path);

        return this;
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder(String.format(Locale.ENGLISH, BASE_URL, width, height, apiKey));

        if (scale != null) {
            sb.append(String.format(Locale.ENGLISH, "&scale=%d", scale));
        }

        if (centerLat != null && centerLng != null) {
            sb.append(String.format(Locale.ENGLISH, "&center=%f,%f", centerLat, centerLng));
        }
        else if (centerLocation != null) {
            sb.append(String.format(Locale.ENGLISH, "&center=%s", centerLocation.replace(" ", "")));
        }

        if (zoom != null) {
            sb.append(String.format(Locale.ENGLISH, "&zoom=%d", zoom));
        }

        if (markerLocations != null) {
            for (MarkerLocation markerLocation: markerLocations) {
                sb.append(String.format(Locale.ENGLISH, "&markers=%s", markerLocation.toString()));
            }
        }

        if (paths != null) {
            for (Path path : paths) {
                sb.append(String.format(Locale.ENGLISH, "&path=%s", path.toString()));
            }
        }

        return sb.toString();
    }

    public URL toUrl() throws MalformedURLException {
        return new URL(this.toString());
    }
}