unavailable for exFAT

[linzh93]

hi , I get your demo and build it, but when the udisk is exFAT, it can not be checked and read，but i saw your project has this partitionTypes, what shall we do to solve or use it , thank you

[magnusja]

If it is MBR and exFAT it should work if you actvate java-fs. I assume you are doing that if you use my demo app?

[Adrian-Rosoga]

Hi Magnus.

I have encountered the same issue with Usbfileman with FAT or exFAT USB sticks.
See below the stacktrace.

What exactly your suggestion "activate java-fs" means? The exception is thrown from the javafs module - is this related to java-fs you mention? I have just gave Usbfileman a go today, didn't dig much into the code. Working with filesystems on USB devices seems involving, I was expecting a walk in the park but it's not the case ;).

Many thanks,

Adrian

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.github.mjdev.usbfileman, PID: 562
    java.lang.NoSuchMethodError: No virtual method position(I)Ljava/nio/ByteBuffer; in class Ljava/nio/ByteBuffer; or its super classes (declaration of 'java.nio.ByteBuffer' appears in /system/framework/core-oj.jar)
        at org.jnode.fs.exfat.ExFatSuperBlock.read(ExFatSuperBlock.java:72)
        at org.jnode.fs.exfat.ExFatFileSystem.<init>(ExFatFileSystem.java:46)
        at org.jnode.fs.exfat.ExFatFileSystemType.create(ExFatFileSystemType.java:37)
        at org.jnode.fs.exfat.ExFatFileSystemType.create(ExFatFileSystemType.java:32)
        at com.github.magnusja.libaums.javafs.JavaFsFileSystemCreator.read(JavaFsFileSystemCreator.java:73)
        at com.github.mjdev.libaums.fs.FileSystemFactory.createFileSystem(FileSystemFactory.kt:57)
        at com.github.mjdev.libaums.partition.Partition$Companion.createPartition(Partition.kt:87)
        at com.github.mjdev.libaums.UsbMassStorageDevice.initPartitions(UsbMassStorageDevice.kt:173)
        at com.github.mjdev.libaums.UsbMassStorageDevice.setupDevice(UsbMassStorageDevice.kt:158)
        at com.github.mjdev.libaums.UsbMassStorageDevice.init(UsbMassStorageDevice.kt:100)
        at com.github.mjdev.libaums.storageprovider.UsbDocumentProvider.addRoot(UsbDocumentProvider.java:416)
...

[magnusja]

Can you try compiling with target Java version 8 instead of 9?

See
apache/felix#114
sannies/mp4parser#323
jetty/jetty.project#3244

[Adrian-Rosoga]

Hi Magnus,

I will get up to speed again with Android development after a break of some time. I am giving you below details about my setup. Can Android Developer even target Java 9?

Target Compatibility shows as options: 1.8 (Java 8), 1.7 (Java 7), 1.6 (Java 6) and Kotlin 1.3. Same for Source Compatibility.

I tried with Target Java 7 - same issue. No stack trace as the debugger was misbehaving.

My questions and some comments:

• Was exFAT tested and blessed? What was the setup?
• Github says "Currently it supports the SCSI command set and the FAT32 file system.", No mention of exFAT or FAT. Documentation behind?
• If answer to exFAT support is yes, can Usbfileman apk be made available somehow (limited release on Google Play?) so that I can try with exFAT on my phone? If it works I will dig further to find out if there's a build problem or whatever.
• Should maybe try with Kotlin build with exFAT?
• Usbfileman is not verbose when it crashes. Maybe I can contribute here to add some info. If added on Google Play it may send back crash info to you. That could help.
• Stick with the master branch? Or have you pushed stuff to have on the develop one?

Thanks for your work, it was an eye opener, I was expecting a walk in the park but looks like user-space fs support is not trivial ;).

My setup:
Android Studio 3.5
Build #AI-191.8026.42.35.5791312, built on August 9, 2019
JRE: 1.8.0_202-release-1483-b03 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Windows 10 10.0

• Using SDK and JRE that come with Android Studio
• Phone is Samsung Galaxy S7
• USB stick formatted on Windows 10, tried with Nikon S6 XQD card as well, same issue

[magnusja]

@azrael8576 Just have a look in the example app code, it us being used there.

@Adrian-Rosoga Good point. Have not tried it in a long time. exFAT is highly experimental probably has performance issues and is pretty buggy. Use at your own risk. This might be a problem with my release of java-fs because I compiled with JDK 11 ... Will try tomorrow

[azrael8576]

@magnusja
Sorry, I didn't describe it in detail.
I successfully built Usbfileman app.
FAT32 file system is work.
But can't work in exFat.
I find out that JavaFsFileSystemCreator Class has this ExFatFileSystemType from javafs module

[azrael8576]

@magnusja
I am trying to use an exFAT USB device. Exception appears here.

libaums/app/src/main/java/com/github/mjdev/libaums/usbfileman/MainActivity.java

Line 776 in 3d05c95

Log.e(TAG, "error setting up device", e);

[magnusja]

What does the exception say?

[azrael8576]

java.io.IOException: Could not read from device, result == -1 errno 0 null

[HBiSoft]

@magnusja

You can cast ByteBuffer to Buffer then you can compile the project with JDK9 and have it running on JDK8.

[dashifuguye]

java.io.IOException: Could not read from device, result == -1 errno 0 null

I get the same error with you, have you fix it when read exFAT?

[shenqinwei]

upgraded to the version 0.7.1 and exfat still doesn't work

[magnusja]

see #235 (comment) for a fix