Integration graphhopper in android with mapforge

Samii_Brhane · September 3, 2021, 5:30am

hi guys am samii brhane and am android developer. i just started a new project … it is food delivery app and i search github and other blogs on how to integrate graphhopper library in android but i coud’nt find any simple and clean method so help.

i have a folder with
edges, properties, geometry, nodes, names, location_index, node_ch_fastest_car,shortcuts_fastest_car
in my asset folder
so how to use these files with graphhopper to find a route between to point in a map?

LarsLehmann · September 3, 2021, 5:55am

does this help?

https://www.graphhopper.com/android/

Samii_Brhane · September 3, 2021, 6:06am

hi lars … thanks for the reply.
i have integrated the graphhopper dependence in android studio from the integration in github but what i don understand is that what file does graphhopper library need for routing
i have eritrea.map , eritrea.osm, and eritrea.osm.pbf files
using cmd graphhopper web jar created catch file like nodes and other files. so how do i use these file in android studio for routing using graphhopper …

Gregws · September 3, 2021, 6:54am

Hiya,
I use .map with mapsforge, this displays the background map.
.osm is OpenStreetMap data, I don’t use but I think this is used to create the pbf? I just download from geofabrik.
.pbf is what graphopper will use to generate your
edges, properties, geometry, nodes, names, location_index, node_ch_fastest_car,shortcuts_fastest_car files.

Depending on your use, set .pbf file and also your processed edges etc folder.
If it can’t find your processed files folder it will create new ones from your pbf.

So to update your files, clear or delete your processed files, point to your new pbf file and have it recreate them.

Then you can assign your start and end lat long points, and return distance, time and path details from your files.

I havent used android but have setup as standalone Java project

devemux86 · September 3, 2021, 7:50am

GraphHopper cannot work with Android scoped storage,
which requires file streams and not file paths.

GraphHopper focus now seems to be the online routing:

github.com/graphhopper/graphhopper

Future of 'Offline' Routing

opened 05:16PM - 28 Feb 20 UTC

closed 12:26PM - 10 Jul 20 UTC

karussell

android ios

The current state of routing on mobile devices (iOS & Android) without internet …access (aka "offline routing") is suboptimal: * The Android support is "okayish", but for a meaningful usage we could need [graph merging](https://github.com/graphhopper/graphhopper/issues/293) or a tiled approach to allow cross-graph routes and a fix for [a strange, per-process virtual memory limit](https://discuss.graphhopper.com/t/spatial-limitation-in-android-offline-on-device/298/13?u=karussell) to allow loading big graphs too e.g. a native DataAccess or file cache approach. There is also still no CI integration for Android, see #803. * Since several releases there is no update of our [iOS port](https://github.com/graphhopper/graphhopper-ios/). Here all the limitations of the [j2objc library](https://github.com/google/j2objc) apply, but it worked surprisingly well and even supports several Java 11 features and without any artificial virtual memory limitation. **Update**: see this new issue: https://github.com/graphhopper/graphhopper-ios/issues/46 * For both platforms we do not have the public transit module as only the core is limited to Java 7. I am really happy that despite these limitations I know there are apps in the app stores that use GraphHopper for offline routing (Android and iOS). And still, we are struggling to continue supporting this as we have to limit ourselves and avoid updating dependencies (see e.g. #1803), stick to Java 7 in the core and also many dependency issues when it comes to Jackson and its annotations and many more design decisions that would be less complicates without "Android Java" in mind. Also there will be [inline types in Java](http://openjdk.java.net/jeps/169), which are already available as experimental feature in JDK 14, which it will be hard to avoid in the core. Previously we have accepted this and I've done lots of testing for Android myself and invested time or provided the map data and apks, but this does not make much sense as I have no real Android- or "app store"-experience. Additionally it is effort that I'm no longer willing to invest. I see the following options: 1. we abandon offline routing and embrace the latest server side Java version in GraphHopper 2. we make it worth to limit ourselves in the core (i.e. implement the missing "production" features and update the iOS port and have real community involvement for this like we already have for other things) 3. make [native GraphHopper](https://github.com/karussell/graphhopper-native-image) working for mobile devices too ([GraalVM native image](https://www.graalvm.org/docs/reference-manual/native-image/) likely combined with [Gluon tools](https://github.com/gluonhq/client-samples/)). For iOS see also https://github.com/oracle/graal/issues/373. This is currently not usable: even a simple HelloWorld is hard to compile. (could work together with option 1). See update. 4. a special Android fork of GraphHopper (suggested from @develar; could also work together with option 1) If no one steps up for contribution in this area in the next months (see for concrete tasks in option 2), then I'm afraid that we'll have to go for option 1 and drop support for Android offline routing. So, if you use GraphHopper for offline routing, now it is the right time to contribute :) ! (@devemux86, @develar, @menion, @johnpercy, @Starcommander)

An Android GraphHopper sample with Mapsforge / VTM exists here:

Samii_Brhane · September 8, 2021, 5:39am

Thanks Gregws , ur the best. u just cleared the path for me.

Samii_Brhane · September 10, 2021, 5:10am

hi gregws … i hv done what u told me and i got some errors like this:

2021-09-09 13:51:40.975 31050-31050/com.gmail.samiibrhane.foodorder E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.gmail.samiibrhane.foodorder, PID: 31050
java.lang.RuntimeException: To avoid reading partial data we need to obtain the read lock but it failed. In /storage/emulated/0/foodorder
    at com.graphhopper.GraphHopper.load(GraphHopper.java:865)
    at com.graphhopper.GraphHopper.importOrLoad(GraphHopper.java:706)
    at com.gmail.samiibrhane.masterapp.MapActivity.getDirections(MapActivity.java:328)
    at com.gmail.samiibrhane.masterapp.MapActivity.access$100(MapActivity.java:68)
    at com.gmail.samiibrhane.masterapp.MapActivity$1.onTap(MapActivity.java:140)
    at org.mapsforge.map.android.input.TouchGestureHandler.onSingleTapConfirmed(TouchGestureHandler.java:265)
    at android.view.GestureDetector$GestureHandler.handleMessage(GestureDetector.java:345)
    at android.os.Handler.dispatchMessage(Handler.java:107)
    at android.os.Looper.loop(Looper.java:237)
    at android.app.ActivityThread.main(ActivityThread.java:8167)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)
 Caused by: java.io.FileNotFoundException: /storage/emulated/0/foodorder/gh.lock: open failed: EACCES (Permission denied)
    at libcore.io.IoBridge.open(IoBridge.java:496)
    at java.io.RandomAccessFile.<init>(RandomAccessFile.java:289)
    at com.graphhopper.storage.NativeFSLockFactory$NativeLock.tryLock(NativeFSLockFactory.java:116)
    at com.graphhopper.GraphHopper.load(GraphHopper.java:864)
    at com.graphhopper.GraphHopper.importOrLoad(GraphHopper.java:706) 
    at com.gmail.samiibrhane.masterapp.MapActivity.getDirections(MapActivity.java:328) 
    at com.gmail.samiibrhane.masterapp.MapActivity.access$100(MapActivity.java:68) 
    at com.gmail.samiibrhane.masterapp.MapActivity$1.onTap(MapActivity.java:140) 
    at org.mapsforge.map.android.input.TouchGestureHandler.onSingleTapConfirmed(TouchGestureHandler.java:265) 
    at android.view.GestureDetector$GestureHandler.handleMessage(GestureDetector.java:345) 
    at android.os.Handler.dispatchMessage(Handler.java:107) 
    at android.os.Looper.loop(Looper.java:237) 
    at android.app.ActivityThread.main(ActivityThread.java:8167) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100) 
 Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)
    at libcore.io.Linux.open(Native Method)
    at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
    at libcore.io.BlockGuardOs.open(BlockGuardOs.java:252)
    at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
    at android.app.ActivityThread$AndroidOs.open(ActivityThread.java:8044)
    at libcore.io.IoBridge.open(IoBridge.java:482)
    at java.io.RandomAccessFile.<init>(RandomAccessFile.java:289) 
    at com.graphhopper.storage.NativeFSLockFactory$NativeLock.tryLock(NativeFSLockFactory.java:116) 
    at com.graphhopper.GraphHopper.load(GraphHopper.java:864) 
    at com.graphhopper.GraphHopper.importOrLoad(GraphHopper.java:706) 
    at com.gmail.samiibrhane.masterapp.MapActivity.getDirections(MapActivity.java:328) 
    at com.gmail.samiibrhane.masterapp.MapActivity.access$100(MapActivity.java:68) 
    at com.gmail.samiibrhane.masterapp.MapActivity$1.onTap(MapActivity.java:140) 
    at org.mapsforge.map.android.input.TouchGestureHandler.onSingleTapConfirmed(TouchGestureHandler.java:265) 
    at android.view.GestureDetector$GestureHandler.handleMessage(GestureDetector.java:345) 
    at android.os.Handler.dispatchMessage(Handler.java:107) 
    at android.os.Looper.loop(Looper.java:237) 
    at android.app.ActivityThread.main(ActivityThread.java:8167) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)

so give me some code guide

Gregws · September 10, 2021, 9:03am

Sorry my dude, I coded for desktop, unsure about android implementation.
Can you share your code?

karussell · September 18, 2021, 9:00am

I have to make this more precise: our focus always was the JVM. The Android VM is not a proper JVM (Google introduced this mess which they called “Java”). And the result is that the routing with GraphHopper surely and easily works offline e.g. on a Desktop. Only for mobile offline routing additional work might be necessary if there is no proper JVM. Furthermore GraphHopper still works on some old and all recent Android VMs. And the community can verify and contribute changes that this still works for future Android versions.

And regarding “GraphHopper cannot work with Android scoped storage” this is true at the moment, but others made GraphHopper working with streams which, due to its offheap nature, might work for the Android use case too, but this wasn’t tested nor contributed.

system · December 17, 2021, 9:00am

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