Metodo login

public static String login(String userid, String pswrd){
   		String username = null;
   		String Password = null;
   			  try {
   				  Class.forName("org.sqlite.JDBC");
   		          String dbURL = "jdbc:sqlite:/C:/Users/Alessandro/Desktop/db/HH_database.db";
   		          Connection conn = DriverManager.getConnection(dbURL);
   		          if (conn != null) {
   		        	  //GetUsername = JOptionPane.showInputDialog("Inserisci l'username");
   		    		  //GetPassword= JOptionPane.showInputDialog("Inserisci la password");
   		              Statement stmt = conn.createStatement();
   		              ResultSet rs;
   		              rs = stmt.executeQuery("SELECT Username, Password, Local_User_ID, Name, Surname FROM User_Data WHERE Username='" + userid + "' AND Password= '" + pswrd + "'");
   		              if(rs.next()){
   		            	  int Local_User_ID = rs.getInt("Local_User_ID");
   		            	  String Username = rs.getString("Username");
   		            	  ArrayList<String> res = new ArrayList<String>();
   		           	      ArrayList<Integer> res_1 = new ArrayList<Integer>();
   		           	      ArrayList<String> res_2 = new ArrayList<String>();
   		            	  String Name = rs.getString("Name");
   		            	  String Surname = rs.getString("Surname");
   		            	  rs = stmt.executeQuery("SELECT Device_Description, D.Local_Device_ID, Feature_ID_List FROM User_Device_Map U, Devices D WHERE U.Local_Device_ID=D.Local_Device_ID AND Local_User_ID= '" + Local_User_ID + "'");
   	     	              while(rs.next()){
   	     	              String Device = rs.getString("Device_Description");
   	     	              String Features_ID_List = rs.getString("Feature_ID_List");
   	    	              int ID = rs.getInt("Local_Device_ID");
   	     	              res.add(Device);
   	     	              res_1.add(ID);
   	     	              res_2.add(Features_ID_List);
   	     	              }
   	     	              d = new InfoDevice(res_1, res, res_2, Local_User_ID);
   		            	  u = new UtenteCurrent(Username, Password, res, res_1);
   		            	  return InfoDevice.toJson(Username, Local_User_ID, Name, Surname, res, res_1, res_2);
   		              }

   		              conn.close();
   		            	  return "Username" + "  " + userid + "  " + "e" + "  " + "Password" + "  " + pswrd + "  " + "Sbagliate";
   		          }

   		      } catch (ClassNotFoundException ex) {
   		          ex.printStackTrace();
   		      } catch (SQLException ex) {
   		          ex.printStackTrace();
   		      }
   			  return "ciao";
   		  }

metodo toJson

public static String toJson(String Username, Integer Local_User_ID, String Name, String Surname, ArrayList <String> a, ArrayList <Integer> b, ArrayList <String> c)
           {
        	   String result = "{\r    ";
        	   result+="\"Username\": \"" + Username + "\",\r    ";
        	   result+="\"ID\": \"" + Local_User_ID + "\",\r    ";
        	   result+="\"Nome\": \"" + Name + "\",\r    ";
        	   result+="\"Cognome\": \"" + Surname + "\",\r    ";
               result+="\"devices\": [\r  ";
               for(int i=0;i<a.size();i++){
                   result+="   {\r";
                   result+="       \"name\": \""+ a.get(i)+ "\",\r";
                   result+="       \"id\": \""+ b.get(i)+ "\",\r";
                   result+="       \"features\": " + "[ "+c.get(i)+" ]\r";
                   result+="      },\r";
               }
               result+="  ]\r}";
               return result;
           }

metodo POST

@POST
    @Produces({MediaType.APPLICATION_JSON})
    @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
    public String sayJSONQuery(
      @FormParam("id") String id,
      @FormParam("pswrd") String pswrd,
      @Context HttpServletResponse servletResponse) throws IOException {
        return UtenteCurrent.login(id, pswrd);
    }