Use java to run a shell script which called a crontab command at Unix

Question

I was trying to write an automate function using Java, which needs to call a shell script containing a crontab commend. The shell works fine without that crontab commend, but once I add it, the program won't execute that crontab commend.
public void cron(){
try
Process proc = Runtime.getRuntime().exec("script1");
BufferedReader br = new BufferedReader(new           InputStreamReader(proc.getInputStream()));
String line;
while ((line = br.readLine()) != null)
     System.out.println(line);
int returnValue = proc.waitFor();
br.close();
} catch (Exception e){} //
script1:
#!/bin/sh
crontab cronfile
Can someone help me out for this? Thank you.

Answer 1

Try this....
Process p = Runtime.getRuntime().exec("sh");
java.io.BufferedWriter bw = new java.io.BufferedWriter(new java.io.OutputStreamWriter(p.getOutputStream()));
bw.write("script1");
bw.flush();
bw.close();