Java调用系统执行程序(OS Command)

public static void main(String args[]) {
String s = null;
// system command to run
String cmd = "cmd /c c:/SayHi.exe";
// set the working directory for the OS command processor
File workDir = new File("c://");

try {
Process p = Runtime.getRuntime().exec(cmd, null, workDir);
int i = p.waitFor();
if (i == 0) {
BufferedReader stdInput =
new BufferedReader(
new InputStreamReader(p.getInputStream()));
// read the output from the command
while ((s = stdInput.readLine()) != null) {
System.out.println(s);
}
} else {
BufferedReader stdErr =
new BufferedReader(
new InputStreamReader(p.getErrorStream()));
// read the output from the command
while ((s = stdErr.readLine()) != null) {
System.out.println(s);
}

}
} catch (Exception e) {
System.out.println(e);
}
}

public class ExecuteCommand{

public static void main(String[] args) throws Exception{
String[] cmd = {"sh","-c","clear"};
//String cmd = "clear";

Runtime rt = Runtime.getRuntime();
rt.exec(cmd);
}
}