B4J Library jShell library

The jShell library allows you to start other programs. It is based on Apache Commons Exec project: http://commons.apache.org/proper/commons-exec/index.html

The programs are always started asynchronously. ProcessComplete event is raised when the process completes.

The following code will run the Java program we previously created:

Sub AppStart (Args() As String)
   Dim shl As Shell
   shl.Initialize("shl", "java", _
     Array As String("-cp", "curl.jar", "b4j.example.main", "http://www.b4x.com"))
   shl.WorkingDirectory = "C:\Users\H\Documents\B4J\Curl\Objects"
   shl.Run(10000) 'set a timeout of 10 seconds
   StartMessageLoop 'need to call this as this is a console app.
End Sub


Sub shl_ProcessCompleted (Success As Boolean, ExitCode As Int, StdOut As String, StdErr As String)
   If Success AND ExitCode = 0 Then
     Log("Success")
     Log(StdOut)
   Else
     Log("Error: " & StdErr)
   End If
   ExitApplication
End Sub

The Shell library can be used in a UI app in the same way.


V1.30 is released - Includes a method to start a process and wait for it to complete. You should normally not use this method in a UI application as it will block the UI thread.

 

[wl]

The example seems to use a Windows folder as the WorkingDirectory.

I guess it can also be used within Linux to launch Linux commands ?

Can it also be used to launch a Linux command which pipes out its output (to be read in the event handler) ?

 

[Erel]

I guess it can also be used within Linux to launch Linux commands ?

Yes.

You can start the bash engine and pass the other programs as parameters. See this answer: http://stackoverflow.com/questions/8243157/building-a-process-pipe-with-processbuilder-in-java-7

 

[peacemaker]

I cannot understand how to run .exe and exit my app. My app closes the starting app2 also when exiting.

 

[Erel]

Please do not post duplicate questions.

 

[imbault]

Hi Erel,

Just a question, how to run a external url from b4j using jshell
like run http://frws016:82/Admin/Order/List

thanks a lot
Patrick

 

[Erel]

What do you mean with run an external url? Do you want to download it? Do you want to show it in a browser?

 

[imbault]

I want to show it in a browser like the command :
start http://frws016:82/Admin/Order/List

 

[Erel]

fx.ShowExternalDocument("your link")

 

[imbault]

Thank you Erel

 

[derez]

The shell works for me only if I change the jar to exe (with launch4j)

shl.Initialize("shl", "server_report.exe", Array As String(name))

otherwise there is an error saying that this is not a windows executable. The application is a UI one.

 

[Erel]

If you just want to start the jar file then you can use fx.OpenExternalDocument. If you want to do it with jShell then you need to start "java.exe -jar <your jar>"

 

[derez]

Thank you. The first option does not work in non Ui .
The shell works with jar like this:

 shl.Initialize("shl", "java.exe" , Array As String("-jar", "Server_report.jar",name))

 

[Gary Miyakawa]

How do you "debug" jshell ? Is there an option to turn on logging ?

Thanks,

Gary M

 

[Erel]

StdOut and StdErr strings hold the process output.

 

[alienhunter]

StdOut and StdErr strings hold the process output.

Hi , is there a way to find out if "example.exe"(dos cmd) has finished downloading a file with Jshell if the "example.exe" does not close if download is complete ?
or i just have to track the bytes written and compare if the file size has changed in the last second
AH

 

[Erel]

You can track the process output by running it with RunWithOutputEvents.

 

[alienhunter]

thanks i will try AH

 

[alienhunter]

You can track the process output by running it with RunWithOutputEvents.

Finaly i got to use this but there is a Message "XML was improperly formatted ..."
it will crash the app
Any clues
thanks AH

 

[Erel]

This message is an IDE error. Ignore it. It has no effect on your app.