Mapy 9300

A map app for the Nokia 9300 / 9500 Communicator (Series 80 v2, Symbian 7.0s, J2ME MIDP 2.0), inspired by the Mapy.com Android app.

Demo 0.9:

• Map: OpenStreetMap tiles (tile.openstreetmap.org), panning and zoom, up to 24 tiles in memory.

• Points of interest overlay (from zoom 16): restaurants, cafés, pubs, accommodation, parking, drinking water, playgrounds, monuments, churches, bells, museums, galleries, theatres, shelters, bunkers, city gates, parks, shops and services. Positions and types come from OpenStreetMap (Overpass API), loaded by cells of the z15 tile grid (~0.8 km): the view's missing cells in one query, each cell then kept in the phone's cache (30 days), so panning back or revisiting needs no request (Reload fetches the view's cells again); they are drawn with the Mapy.com map icons (res/poi_icons16.png, made from the icons the Mapy.com app loads from api.mapy.cz/poiimg/icon). A click opens the same place in Mapy.com (search by name nearby, then getDetail); without a match it shows the OSM data.

• Photos: the detail shows the place's main photo; "Fotky (N)" opens a full-screen gallery (arrows = next). Photos come from Seznam's image servers in a size that fits the screen (?fl=res,,<height>,3).

• Hover preview: when the cursor rests on an object for a second, the panel shows its Mapy.com rating and a small photo (can be switched off in Settings; costs a few requests per object).

• Caching: map tiles and photos are kept in an LRU cache in the phone's record store (RMS, no permission prompts), 16 MB by default, set in Settings (0–48 MB, "Clear cache"). Entries older than 30 days are fetched again. In memory: the last 24 tiles, 12 photos and 40 Mapy.com details.

• Search: Mapy.com suggestions (vectmap.mapy.cz/rpc, FastRPC suggest) near the map view; the chosen result gets a red pin.

• Place detail: Mapy.com getDetail (address, rating, description, facts).

• What's here: Mapy.com detail of the map centre.

• Bluetooth GPS: position from a Bluetooth GPS receiver or an Android phone sharing its GPS as NMEA over Bluetooth (address in Settings; Menu → GPS connect). Blue dot with heading; "My position" follows it.

• Routes and navigation (walking and car): detail of a place → "Route here on foot / by car", from the GPS position (or, without GPS, from the map cursor). The route comes from OSRM on the FOSSGIS server (routing.openstreetmap.de, OpenStreetMap data: full line + turn steps; max 1 request/s, no heavy use). Menu → "Navigation start": the map follows the GPS, the panel shows the next instruction ("In 80 m: Turn left onto Křížkovského"), the remaining distance and time; off the route (30 m on foot, 50 m by car, 3 fixes in a row) it recalculates, at most every 15 s. Mapy.com's own routes can't be used for this yet: their full line is in an encoded format; see ../mapy/ANALYSIS.md. With your own Mapy.com API key (Settings → Mapy.com API key; Load from the PC reads mapy_api.key next to the kit's ota_server.js, gitignored) routes come from the official Mapy.com REST API instead (api.mapy.com/v1/routing/route, 4 credits each, free plan 250,000 credits a month): cars use car_fast_traffic (current traffic in Czechia), "no toll roads" is avoidToll. That API gives no turn instructions, so they are made from the line's bends (no street names). If the Mapy.com request fails, OSRM is used as before.

Map types: measured speed

Network time per tile on the Nokia 9300 (Probe 3.4 Map servers test, average of 4 runs, 2026-10-06, internet over USB from a PC; the first tile of each series left out). The map type list shows these.

Map type	Direct	Through Net Helper
OpenStreetMap (HTTPS)	0.7 s	0.2 s
OpenTopoMap (HTTP)	0.5 s	0.2 s
ČÚZK base map (HTTP, 30–40 KB JPEG)	0.6 s	0.4 s
ČÚZK aerial (HTTP)	0.6 s	0.4 s
Mapy.com outdoor (HTTPS, API key)	1.7 s	0.3 s
Mapy.com aerial (HTTPS, API key)	1.6 s	0.3 s
Mapy.com standard (HTTPS, API key)	1.5 s	0.3 s

Without Net Helper every HTTPS tile pays a new TLS handshake (Mapy.com ~1 s); the servers themselves answer in 60–220 ms. Decoding on the phone comes on top (JPEG ~200 ms, PNG 300–500 ms).

Controls

Full screen: an info panel on the left (progress, status, the object under the cursor, zoom, credits; width set in Settings), the map, and a thin icon bar on the right that labels the four side buttons (in full screen the phone doesn't draw their labels). The map has a Windows-XP-style mouse cursor. The 9300's Java has no pointer events, so the navigation key drives it: it moves while held (time-based speed that accelerates, so the 9300's coarse timer doesn't make it jerky), diagonally when two directions are held, and at the edge of the map the map scrolls.

Key	Action
Navigation key / arrows	move the cursor; the map scrolls at the edge
Side buttons (top to bottom)	Search, Zoom in, Zoom out, Menu (set up once: Menu → Set up side buttons)
+ / - (also 3 / 1)	zoom in / out around the cursor
Enter / navigation key press	click: open the object under the cursor, or "what's here" at the cursor
N / space	jump the cursor to the next object on screen
0	full screen on/off
letters	shortcuts (H search, T route, P my position, M map type, S follow, G GPS, V navigation, …); Tab opens the menu, which lists them

Objects under the cursor are highlighted like a link (blue ring, underlined label, name in the panel). The panel shows the code of the last key pressed, and every key is logged. Chr + Up/Down can't zoom: the 9300 doesn't tell Java about the Chr key (Chr alone sends nothing, Chr+Up arrives as a plain Up, -1), so zoom is on the side buttons and + / -.

How it talks to the network (Nokia 9300 rules)

• HTTPS through HttpConnection and the patched SSLADAPTOR.dll (janseris/symbian-tls v20-fix10); no signing needed.
• Net.java: one request at a time, each attempt on its own thread, abandoned (never closed from another thread) after 15 s without progress, 3 attempts, a short pause after each request so the phone keeps answering the PC's USB keep-alive. Progress is shown in the bottom strip, and only that strip (or the arriving tile) is repainted while loading.
• Our own User-Agent (Mapy9300/0.9 (+https://github.com/janseris/mapy-j2me)), as OSM's tile and Overpass policies require; tiles only for the visible area, no prefetching.
• Mapy.com calls: the FastRPC requests captured from the Android app (encoder verified byte for byte against the capture), without key or login.

Credits: map data and POIs © OpenStreetMap contributors (ODbL). Search, details and the POI icons: Mapy.com (Seznam.cz). This is a non-commercial hobby project, not affiliated with Seznam.cz.

Build

build.bat (uses the JDK 8, stub jars and ProGuard bundled in pubtran-j2me, cloned next to this repo). Raise MIDlet-Version in manifest.mf first. Output: bin/mapy9300.jar + .jad. run_kemulator.bat starts it in KEmulator. Request log: menu Log → Odeslat log na PC (ota_server.js from android-to-j2me-kit or pubtran-j2me on the PC, port 8000).