I have learnt to read and write an Excel file using a Java program with the help of Jxl and POI API. Is it possible to run a Java program with the help of macros?
Yes, it is possible.
There are quite a few ways actually and I hope you like my examples.
To demonstrate this, I create a program where some text is send as arguments and program responds with an altered version of it. I made a runnable jar of it. First example reads the argument from args and other from standard input.
File Hello.java and H1.jar:
public class Hello {
public static void main(String[] args) {
StringBuilder sb = new StringBuilder("Hello");
if (args.length > 0)
sb.append(' ').append(args[0]);
System.out.println(sb.append('.').toString());
}
}
File Hello2.java and H2.jar:
import java.util.Scanner;
public class Hello2 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
StringBuilder sb = new StringBuilder("Hello");
sb.append(' ').append(sc.nextLine());
System.out.println(sb.append('.').toString());
}
}
You can save them in a single jar, but then you need create and use a manifest (that's a bit overkill).
Now in Excel I add a module and a reference to Windows Script Host Object. If you do not like the sleep
, then you can replace it with DoEvents
:
'add a reference to Windows Script Host Object Model
'for example : Tools-References
Option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Private Sub RunSleep( _
exec As WshExec, _
Optional timeSegment As Long = 20 _
)
Do While exec.Status = WshRunning
Sleep timeSegment
Loop
End Sub
Private Function RunProgram( _
program As String, _
Optional command As String = "" _
) As WshExec
Dim wsh As New WshShell
Dim exec As WshExec
Set exec = wsh.exec(program)
Call exec.StdIn.WriteLine(command)
Call RunSleep(exec)
Set RunProgram = exec
End Function
And to test it I saved the files to c:\
drive and used the code:
Public Sub Run()
Dim program As WshExec
Set program = RunProgram("java -jar ""C:\\H1.jar"" Margus")
Debug.Print "STDOUT: " & program.StdOut.ReadAll
Set program = RunProgram("java -jar ""C:\\H2.jar", "Margus")
Debug.Print "STDOUT: " & program.StdOut.ReadAll
End Sub
In my case I get a responce of :
STDOUT: Hello Margus.
STDOUT: Hello Margus.