Android Question File Uri Exposed Error

[peggjones]

I have just changed an app to target SDK version 26 and am getting the above error. Is there anyway to just suppress this error rather than recoding to use file picker? It will involve quite a lot of work for me (I have several app that would need changing.

 

[DonManfred]

https://www.b4x.com/android/forum/t...etsdkversion-minsdkversion.87610/#post-554210

especially
- 24 - must use FileProvider when sharing files (https://www.b4x.com/android/forum/t...om-your-app-with-file-provider.70458/#content)

 

[Erel]

It is not possible to suppress this error. You must use FileProvider.

 

[peggjones]

Thanks. I that would be the case. Is there any documentation for fileprovider. I've searched the forum and can only find examples. I want to be able to add file names and paths to a database and later open and display the documents. Many thanks.

 

[DonManfred]

Search google for any android documentation about fileprovider

 

[Erel]

FileProvider tutorial: https://www.b4x.com/android/forum/threads/sharing-files-from-your-app-with-file-provider.70458/
There are links to all kinds of examples.

I want to be able to add file names and paths to a database and later open and display the documents.

You need to provide more information. Are you using ContentChooser? How are you getting the files?

 

[peggjones]

I am having a problem at the moment with displaying a word document the address of which is held on database.

The error I get is java.lang.reflect.InvocationTargetException

    filepath1 = Main.SQL.execQuerySingleResult("SELECT path FROM Attachments where attachno = " & QUOTE & Main.attachno & QUOTE)
    filename1 = Main.SQL.execQuerySingleResult("SELECT filename FROM Attachments where attachno = " & QUOTE & Main.attachno & QUOTE)
    filepath1 = filepath1 & "/" & filename1
   
' Dummy is just a convenient file to have put in DIRASSETS.
' Copy file from Database to DIRASSETS

    File.Copy(File.DirAssets, "Dummy.docx", Starter.shared, filename1)
    Dim in As Intent
   
' Get URL of the file now in DIRASSETS

    in.Initialize(in.ACTION_VIEW, CreateFileProviderUri(Starter.shared, "Dummy.docx"))
    in.Flags = 1

Sub CreateFileProviderUri (dir As String, filename2 As String) As Object
    Dim FileProvider As JavaObject
    Dim context As JavaObject
    context.InitializeContext
    FileProvider.InitializeStatic("android.support.v4.content.FileProvider")
    Dim f As JavaObject
    f.InitializeNewInstance("java.io.File", Array(dir, filename2))
    Return FileProvider.RunMethod("getUriForFile", Array(context, Application.PackageName & ".provider", f))

End Sub

Many Thanks

 

[Erel]

The error I get is java.lang.reflect.InvocationTargetException

You should post the full error message from the logs.
Also write which line causes this error.

Tip:
You should never write:

filename1 = Main.SQL.execQuerySingleResult("SELECT filename FROM Attachments where attachno = " & QUOTE & Main.attachno & QUOTE)

You should write:

filename1 = Main.SQL.execQuerySingleResult2("SELECT filename FROM Attachments where attachno = ?", Array As String(Main.attachno))

 

[peggjones]

Thanks for tip I'll do it like that in future.

The line causing the error is

Return FileProvider.RunMethod("getUriForFile", Array(context, Application.PackageName & ".provider", f))

The full error message is

20180328192049_IMG_0055.JPG
/storage/emulated/0/bossfolder/VocabDocs
PronunciationNotes.doc
Error occurred on line: 580 (Listattachments)
java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4j.object.JavaObject.RunMethod(JavaObject.java:131)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:339)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:139)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:170)
at anywheresoftware.b4a.debug.Debug.delegate(Debug.java:259)
at b4a.Checklist.listattachments._createfileprovideruri(listattachments.java:1374)
at b4a.Checklist.listattachments._docbutt_click(listattachments.java:1452)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:342)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:139)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:170)
at anywheresoftware.b4a.BA.raiseEvent(BA.java:166)
at anywheresoftware.b4a.objects.ViewWrapper$1.onClick(ViewWrapper.java:80)
at android.view.View.performClick(View.java:6257)
at android.widget.TextView.performClick(TextView.java:11149)
at android.view.View$PerformClick.run(View.java:23705)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6780)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1496)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.ProviderInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference
at android.support.v4.content.FileProvider.parsePathStrategy(FileProvider.java:604)
at android.support.v4.content.FileProvider.getPathStrategy(FileProvider.java:578)
at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:416)
... 31 more
** Service (starter) Destroy **

 

[Erel]

I don't really understand your code. Seems to me that it should be:

in.Initialize(in.ACTION_VIEW, CreateFileProviderUri(Starter.shared, filename1))

 

[peggjones]

I think I need to understand more about this whole process. I have very limited knowledge. It took me ages to get the process to work using the "old" method like this

    Dim I As Intent
    I.Initialize(I.ACTION_VIEW, "file:///" & filepath)
    I.SetComponent(" ")
    StartActivity(I)

I am now trying to update my so that it will work targeting SDK 26.

The problem I have (which is entirely my fault) is that with my lack of knowledge I am having trouble adapting the sample code to work with a path from my database

Sub Button1_Click
    'copy the file to the shared folder
    File.Copy(File.DirAssets, "b4a.png", Starter.shared, "b4a.png")
    Dim in As Intent
    in.Initialize(in.ACTION_VIEW, CreateFileProviderUri(Starter.shared, "b4a.png"))
    in.Flags = 1
    StartActivity(in)
End Sub


Sub CreateFileProviderUri (Dir As String, FileName As String) As Object
    Dim FileProvider As JavaObject
    Dim context As JavaObject
    context.InitializeContext
    FileProvider.InitializeStatic("android.support.v4.content.FileProvider")
    Dim f As JavaObject
    f.InitializeNewInstance("java.io.File", Array(Dir, FileName))
    Return FileProvider.RunMethod("getUriForFile", Array(context, Application.PackageName & ".provider", f))
End Sub

I'll go back to the drawing board! Don't spend any more time on it.

Many Thanks for trying

 

[Erel]

You are not following the relevant example. You need this one:
- Example of sharing a file (any file): https://www.b4x.com/android/forum/threads/share-txt-files.73166/#post-464921