B4J Question Check if number is greater less

sigster

Active Member
Licensed User
Hi

I am try to check if the app have new version
this is my code I am getting error java.lang.NumberFormatException: multiple points

Regards
Sigster


B4X:
    Dim app_version As String = "1.0.1"   
    Dim upgrade As String


        If app_version < upgrade.check_upgrade Then
        Txt_yesorno.Text = "Yes"
        Else
        Txt_yesorno.Text = "No"
        End If

       
Sub check_upgrade

ConnectDatabase
       
Dim RS As ResultSet = SQLCon.ExecQuery("SELECT * FROM version " WHERE ID = '1';")
Do While RS.NextRow
   
    upgrade = RS.GetString("version")
   
Loop

RS.Close

End Sub
B4X:
main._appstart (java line: 150)
java.lang.NumberFormatException: multiple points
    at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1110)
    at java.lang.Double.parseDouble(Double.java:540)
    at b4j.example.main._appstart(main.java:150)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:93)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:84)
    at b4j.example.main.start(main.java:36)
    at com.sun.javafx.application.LauncherImpl$5.run(LauncherImpl.java:319)
    at com.sun.javafx.application.PlatformImpl$5.run(PlatformImpl.java:219)
    at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:182)
    at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:179)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl$4.run(PlatformImpl.java:179)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:76)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:17)
    at com.sun.glass.ui.win.WinApplication$3$1.run(WinApplication.java:67)
    at java.lang.Thread.run(Thread.java:745)
 

derez

Expert
Licensed User
The query
B4X:
SQLCon.ExecQuery("SELECT * FROM version " WHERE ID = '1';")
should be

B4X:
SQLCon.ExecQuery2("SELECT * FROM version WHERE ID = ? ",Array As String(1))
What is upgrade ? a module ? then it is wrong to dim it as a string. Do not use one name for many objects.
The comparison of "<" between strings does not make too much sense.
 
Last edited:

DarkMann

Member
Licensed User
Because your version number is actually a string (with 2 points in it, not 1 like a decimal number) you will have to use CompareTo on the strings.

B4X:
Dim app_version As String = "1.0.1"  
Dim upgrade As String = "1.0.2"  ' or whatever

    If app_version.CompareTo(upgrade)<0 then
        Txt_yesorno.Text = "Yes"
        check_upgrade
    Else
        Txt_yesorno.Text = "No"
    End If

' rest of code
see http://www.b4x.com/b4j/help/core.html#string_compareto

Like Troberg, I've always done it with > or < in other basics, but I guess it's something to do with the Java underpinnings of B4A and B4J that make that just not possible.

David
 

Troberg

Well-Known Member
Licensed User
Wow, I've missed that. I don't think it breaks anything for me in my current code, but it's a nasty bug risk if you are not aware of it.

In the sampe above, I'd simply test to see if the version is different from the current version. If, for some odd reason, the installed version is newer than the current version, something is very wrong and installing the current version seems prudent anyway.
 

sigster

Active Member
Licensed User
Thanks for the help :)

this is how I use it when I start the app I check for upgrade and if it is new upgrade I download the new file overwrite the app file and restart the app



B4X:
Dim app_version As String = "1.0.1"  

check_upgrade(app_version,upgrade)

Sub check_upgrade(AppVersion As String,NewVersion As String)
          Dim job As HttpJob
        Dim NewFile As String
  
         If AppVersion.Compareto(NewVersion) < 0  Then
                Log("Upgrade")
                Dim job As HttpJob
                Dim NewFile As String
                NewFile = "http://PATH-TO-THE-FILE"
                job.Initialize("DownloadFILE", Me)
                job.Tag = NewFile
                job.download(NewFile)
             Else If AppVersion.Compareto(NewVersion) > 0 OR AppVersion.Compareto(NewVersion) = 0 Then                              
                Log("No upgrade")
          End If
End Sub
 

derez

Expert
Licensed User
B4X:
   Else If AppVersion.Compareto(NewVersion) > 0 OR AppVersion.Compareto(NewVersion) = 0 Then
Just Else will do the same...
 
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