Kode Otomatis Java Netbeans Berdasarkan Tanggal

Sandi Fadilah 2/21/2017 Java Netbeans

   public void auto_key(){  
   try {  
   java.util.Date tgl = new java.util.Date();  
   java.text.SimpleDateFormat kal = new java.text.SimpleDateFormat("yyMMdd");  
   java.text.SimpleDateFormat tanggal = new java.text.SimpleDateFormat("yyyyMMdd");  
     Connection c=ClassKoneksi.getkoneksi();  
     String sql = "select max(supplier_id) from t_supplier WHERE supplier_input ="+tanggal.format(tgl);   
     Statement st = ClassKoneksi.getkoneksi().createStatement();  
     ResultSet rs = st.executeQuery(sql);  
     while(rs.next()){  
     Long a =rs.getLong(1); //mengambil nilai tertinggi  
       if(a == 0){  
         this.supplier_id.setText(kal.format(tgl)+"0000"+(a+1));  
       }else{  
         this.supplier_id.setText(""+(a+1));  
       }  
   }  
   rs.close(); st.close();}  
   catch (Exception e) {  
   JOptionPane.showMessageDialog(null, "Terjadi kesalaahan");  
   }  
 }