问从java调用gnuplot？(ubuntu)

EN

String[] s = {"/usr/bin/gnuplot",
              "-e",
              "set term jpeg large size 800,600;set autoscale; set grid;set format y \"%0.f\";set output \"plot.jpg\";set xdata time;set timefmt \"%Y-%m-%d-%H:%M:%S\";set xlabel \"Dates\";set ylabel \"Data transferred (bytes)\";plot \""+x+"\" using 1:2 title \"Total:"+tot+"\" with linespoints;"
             };
try {
    Runtime rt = Runtime.getRuntime();
    Process proc = rt.exec(s);
    InputStream stdin = proc.getErrorStream();
    InputStreamReader isr = new InputStreamReader(stdin);
    BufferedReader br = new BufferedReader(isr);
    String line = null;
    while ((line = br.readLine()) != null)
        System.err.println("gnuplot:"+line);
    int exitVal = proc.waitFor();
    if (exitVal != 0)
        log("gnuplot Process exitValue: " + exitVal);
    proc.getInputStream().close();
    proc.getOutputStream().close();
    proc.getErrorStream().close();
} catch (Exception e) {
    System.err.println("Fail: " + e);
}