java - Java类型不匹配？

Question

好的，所以我必须创建一个程序，它是 parking 票模拟器。我编译了它，并且在大多数情况下都可以工作，除了我得到的这个小傻瓜错误外，这是类型不匹配。有很多代码，所以我只给错误是的类:

KNW_PoliceOfficerClass

public class KNW_PoliceOfficer 
{ 
  private String name;
  private int badge;
  private static double ticket;

      public KNW_PoliceOfficer() 
      {

      }

      public KNW_PoliceOfficer(String poName, int poBadge) 
      {
        name = poName;
        badge = poBadge;
      }

      public String getName() 
      {
        return name;
      }
      public int getBadge() 
      {
        return badge;
      }

      static KNW_ParkingTicket search(KNW_ParkedCar car, KNW_ParkingMeter meter) 
      {
        int time = KNW_ParkedCar.getMinutes() - KNW_ParkingMeter.getMinPurchased();

        if(KNW_ParkedCar.getMinutes() > KNW_ParkingMeter.getMinPurchased()) 
        {
          if(time <= 60) 
          {
            ticket = 25;
          }
          else 
          {
            ticket = 25 + (10 * (time/60));
          }
          return ticket;
        }


      }

KNW_ParkingTicketClass

 public class KNW_ParkingTicket 
{
  private KNW_ParkedCar vehicle;
  private KNW_PoliceOfficer copster;
  private double fine;
  private int minutes;
  private double firstFine = 25;
  private double moreFine = 10;

  public KNW_ParkingTicket(KNW_ParkedCar car, KNW_PoliceOfficer cop, double guyFine, int mins) 
  {
   vehicle = car;
   copster = cop;
   fine = guyFine;
   minutes = mins;
  }

  public void getTotalFine() 
  {
   int  time = KNW_ParkedCar.getMinutes() - KNW_ParkingMeter.getMinPurchased();

   if(time <= 60) 
   {
    fine = firstFine;
   }
   else 
   {
    fine = firstFine + moreFine * (time / 60);
   }
  }

  public double getFirstFine() 
  {
   return firstFine;
  }
  public double getMoreFine() 
  {
   return moreFine;
  }
  public KNW_ParkedCar getVehicle() 
  {
   return vehicle;
  }
  public KNW_PoliceOfficer getCopster() 
  {
   return copster;
  }
  public int getMinutes() 
  {
   return minutes;
  }
  public double getFine() 
  {
   return fine;
  }


 }

这是错误的意思:

 File: C:\Users\Kyle Welch\KNW_PoliceOfficer.java  [line: 46]
Error: Type mismatch: cannot convert from double to KNW_ParkingTicket

任何帮助，将不胜感激!

Answer 1

问题出在ticket参数上，您以这种方式定义了它:double ticket;
在KNW_ParkingTicket方法中，您可以在此处看到带有参数的完整方法:
static KNW_ParkingTicket search(KNW_ParkedCar car, KNW_ParkingMeter meter)
它需要返回一种KNW_ParkingTicket类型，但是您要在其中返回一个名为double的ticket:
return ticket;