Execute a Java program from our Java program

Question

I used

Runtime.getRuntime().exec("_____")

but it throws a IOException as below:

java.io.IOException: CreateProcess: c:/ error=5
  at java.lang.Win32Process.create(Native Method)
  at java.lang.Win32Process.<init>(Win32Process.java:63)
  at java.lang.Runtime.execInternal(Native Method

I don't know whether I have the problem with specifying the path or something else. Can anyone please help me with the code.

Answer 1

You're trying to execute "C:/". You'll want to execute something like:

"javaw.exe d:\somejavaprogram\program.jar"

Notice the path separators.

I'm assuming this is for an ad-hoc project, rather than something large. However, for best practice running external programs from code:

• Don't hardcode the executable location, unless you're certain it will never change
• Look up directories like %windir% using System.getenv
• Don't assume programs like javaw.exe are in the search path: check them first, or allow the user to specify a location
• Make sure you're taking spaces into account: "cmd /c start " + myProg will not work if myProg is "my program.jar".