ClassCastException不能将Class.Accomodation转换为Class.Auttraction

Question

这些是我的蒙德尔人：

public class Accomodation {
    ...
}

而且

public class Attraction extends Accomodation {
    ... 
    private String openingTime;
}

我的Controller类中有这个方法：

protected Accomodation getAccomodationByFormData(CrudView crudView) {
        Accomodation accomodation = new Accomodation();
        // setters
        return accomodation;
    }

在attractioncontroller（扩展以前的controller)中使用：

@Override
    protected Accomodation getAccomodationByFormData(CrudView crudView) {
        Attraction attraction = (Attraction) super.getAccomodationByFormData(crudAttractionView);
        attraction.setOpeningTime(getOpeningTimeWithFormData()); 
        return attraction;
    }

在此attractioncontroller的另一点中，我有：

...
Attraction attraction = (Attraction) getAccomodationByFormData(crudAttractionView); // throws ClassCastException
...

但这给了我：

线程“JavaFX Application thread”java.lang.ClassCastException：类Models.Accomodation不能强制转换为类Models.Intraction（Models.Accomodation和Models.Intraction在Controllers.CrudattractionController.GetAccomodationByFormData（CrudattractionController.java:302)在Controllers.CrudattractionController.lambda$ButtonConferMacLicked$4(CrudattractionController.java:143)在un.javafx.event.EventDispatchChainImpl.DispatchEvent（EventDispatchChainImpl.java：114）在javafx.base/com.sun.javafx.event.base/com.sun.javafx.event.dispatchEvent（BasicEventDispatchChainImpl.java：56）在javafx.base/com.sun.javafx.event.dispatchEvent（BasicEventDispatchChainImpl.dispatchEvent（trol.inputmap.inputmap.handle（inputmap.java:274)在javafx.base/com.sun.javafx.event.compositeEventHandler$normalEventHandlerRecord.handleBubblingEvent（compositeEventHandler.java:218)在javafx.base/com.sun.javafx.event.compositeEventHandler.dispatchBubblingEvent（compositeEventHandler.java:80)在tchEvent（EventDispatchChainImpl.java：114）在javafx.base/com.sun.javafx.event.basicEventDispatchEvent（BasicEventDispatchChainImpl.dispatchEvent（BasicEventDispatchChainImpl.java：56）在javafx.base/com.sun.javafx.event.event.dispatchEvent（EventDispatchChainImpl.dispatchEvent（EventDispatchChainImpl.java：114）在java.base/java.security.accesscontroller.doprivileged（本机方法）javafx.graphics/com.sun.javafx.tk.quantum.glassvieweventhandler.lambda$HandleMoseEvent$2(Glassvieweventhandler.java:434)javafx.graphics/com.sun.javafx.tk.quantum.quantumtoolkit.runwithoutrenderlock(quantumtoolkit.java:390)

（ps.请注意，CrudattractionView类扩展了CrudView)

• 如何修复？

编辑

吸引力

public class Attraction extends Accomodation {
    private String openingTime;

    public Attraction() {

    }

    public Attraction(Accomodation accomodation) {
        super(accomodation);
    }

    // getters and setters
}

住宿

public class Accomodation implements Serializable {
    protected String id;
    protected String name;
    protected Integer avarageRating;
    protected Integer avaragePrice;
    protected String phoneNumber;
    protected Address address;
    protected Point point;
    protected List<Review> reviews;
    protected Long totalReviews;
    protected Long totalRating;
    protected List<String> images;
    protected boolean hasCertificateOfExcellence;
    protected String addedDate;
    protected String lastModificationDate;

    public Accomodation() {

    }

    public Accomodation(Accomodation accomodation) {
    }

    // getters and setters
}

Answer 1

所有吸引都是住宿，但不是所有住宿都是吸引。

这意味着您不能安全地执行以下操作：

Attraction attraction = (Attraction) super.getAccomodationByFormData(crudAttractionView);

即使您在attractioncontroller中（Java不会根据您的控制器名称更改super.getaccomadation的返回类型）。

一种不需要任何框架的解决方案是：

Accomodation accomodation = super.getAccomodationByFormData(crudAttractionView);
Attraction attraction = new Attraction(accomodation);
attraction.setOpeningTime(getOpeningTimeWithFormData())

您只需确保您有一个accomodation构造函数，它将接受accomodation并将其字段复制到您的景点。

类似于：

public Attraction(Accomodation accomodation){
  attraction.setX(accomodation.getX())
  ...
}

或者只调用super(accomodation)并在accomodation中使用一个构造函数，该构造函数将能够将一个accomodation复制到一个新的accomodation中（这样您就可以在以后的所有扩展类中使用该构造函数）

现在，你确保你的住所是一个有效的吸引力，然后你投下它。

在一个更简洁的示例中，下面是它的外观

import java.io.Serializable;

class Attraction extends Accomodation {

    public Attraction() {

    }

    public Attraction(Accomodation accomodation) {
        super(accomodation); // we let super do the simple mapping
    }

    // getters and setters

    public void setOpeningTime(String test){
        //

    }
    protected Accomodation getAccomodationByFormData() {
        Accomodation accomodation= new Accomodation();//super.getAccomodationByFormData(crudAttractionView);
        Attraction attraction = new Attraction(accomodation); // we convert our accomodation thanks to our constructor
        attraction.setOpeningTime("...");
        return attraction;
    }
}

class Accomodation implements Serializable {
    protected String id;
    protected String name;
    protected Integer avarageRating;
    protected Integer avaragePrice;
    protected String phoneNumber;
    protected Long totalReviews;
    protected Long totalRating;
    protected boolean hasCertificateOfExcellence;
    protected String addedDate;
    protected String lastModificationDate;

    public Accomodation(Accomodation accomodation) {
        this.id = accomodation.id;
        this.name = accomodation.name;
        this.avarageRating = accomodation.avarageRating;
        this.avaragePrice = accomodation.avaragePrice;
        this.phoneNumber = accomodation.phoneNumber;
        this.totalReviews = accomodation.totalReviews;
        this.totalRating = accomodation.totalRating;
        this.hasCertificateOfExcellence = accomodation.hasCertificateOfExcellence;
        this.addedDate = accomodation.addedDate;
        this.lastModificationDate = accomodation.lastModificationDate;
    }

    public Accomodation() {

    }

    // getters and setters
}