try {
        String path = "ruta_donde_repaldar"
        Runtime r = Runtime.getRuntime();

        //PostgreSQL variables
        String user = "postgres";
        String dbase = "base_datos";
        String password = "tu_clave";
        Process p;
        ProcessBuilder pb;

        /**
         * Ejecucion del proceso de respaldo
         */
        r = Runtime.getRuntime();
        pb = new ProcessBuilder("pg_dump", "-v", "-D", "-f", path, "-U", user, dbase);
        pb.environment().put("PGPASSWORD", password);
        pb.redirectErrorStream(true);
        p = pb.start();

    } catch (Exception e) {
}