create or replace and compile java source 
named "shellcmd"
as
import java.io.*;
import java.lang.*; 
public class shellcmd extends Object
{
  public static int runcmd(String args)
  {
    Runtime rt = Runtime.getRuntime();
    int RC = -1; 
    try
    {
      Process p = rt.exec(args);
      
      int bufSize = 4096; 
      BufferedInputStream bis =new BufferedInputStream(p.getInputStream(), bufSize);
      
      int len;
      byte buffer[] = new byte[bufSize];
      while ((len = bis.read(buffer, 0, bufSize)) != -1)
        System.out.write(buffer, 0, len);
      
      RC = p.waitFor();
    }
    catch (Exception e)
    {
      e.printStackTrace();
      RC = -1;
    }
    finally
    {
      return RC;
    }
  }
}

create or replace procedure cmdshell(command in varchar2)
as
language java name 'shellcmd.runcmd(java.lang.String)';

exec dbms_java.grant_permission('SYSTEM','SYS:java.io.FilePermission','<<ALL FILES>>','execute');

-- 调用存储过程执行系统命令
set serveroutput on
exec dbms_java.set_output(100000);
exec cmdshell('...');