[JAVA - MYSQL] problema con mysqldump

[tommisceddu]

try 
        {
            String command =  "cmd /c start mysqldump.exe"; 
            String[] env = new String[] {"--opt", "--u", "root", "--password=\"12345\"", 
                    "assistiti_db", ">", "C:/backup_db.sql"}; 
            File dir = new File("C:/Programmi/MySQL/MySQL Server 4.1/bin/"); 
            Process p1 = Runtime.getRuntime().exec(command, env, dir);
            
            InputStream err = p1.getErrorStream();
            InputStream in = p1.getInputStream();

            System.out.println("error: " + err.toString());
            System.out.println("input: " + in.toString());
            System.out.println("\nerror: " + err.read());
            System.out.println("input: " + in.read());
        } 
        catch (Exception ex) { ex.printStackTrace(); }

RISULTATO:

error: java.io.FileInputStream@150bd4d
input: java.io.BufferedInputStream@1bc4459

error: -1
input: -1

cosa vuol dire? dove posso cercare i codici d'errore?