Execute a Java program from our Java program

Question

I used

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

but it throws a IOException as below:

java.io.IOException: Create         


        

Answer 1

I had to do this recently.
Here is how I did it, picking up only the relevant parts:

private static final String[] straJavaArgs =
{
   "?i/j2re/bin/java",
   "-ms64m",
   "-mx64m",
   "-Djava.ext.dirs=?i/lib;?i/jar/lib;?i/jar"
};

// ...

  // AppDesc appToRun;
  List params = new ArrayList();
  // Java exe and parameters
  params.addAll(ExpandStrings(straJavaArgs));
  // Common VM arguments
  params.addAll(Arrays.asList(AppDesc.GetCommonVMArgs()));
  // Specific VM arguments
  params.addAll(ExpandStrings(appToRun.GetVMArgs()));
  // The program to run
  params.add(appToRun.GetClass());
  // Its arguments
  params.addAll(ExpandStrings(appToRun.GetProgramArgs()));
  // The common arguments
  params.addAll(ExpandStrings(AppDesc.GetCommonProgramArgs()));

  ProcessBuilder processBuilder = new ProcessBuilder(params);
  process = processBuilder.start();
  return CaptureProcessOutput(); // Uses a StreamGobbler class

protected ArrayList ExpandStrings(String[] stra)
{
  ArrayList alResult = new ArrayList();
  for (int i = 0; i < stra.length; i++)
  {
     // Super flexible, eh? Ad hoc for the current task, at least...
     alResult.add(stra[i]
           .replaceAll("\\?i", strInstallDir)
           .replaceAll("\\?c", strConfigDir)
     );
  }
  return alResult;
}

public enum AppDesc
{
// Enumerate the applications to run, with their parameters
}

Incomplete, if you need more details, just ask.