所以我有一个项目，其中我有一个特定的问题，如果我们正确回答它，就会得到一定数量的分数，该分数根据问题的主题而变化。我有一个名为 Pergunta(Question) 的类，其中包含不同主题的子类，例如 PerguntasArtes(ArtQuestions)，我想在每个子类中编写一个方法来进行积分计算。
public class Pergunta {
private String area;
private String pergunta;
private ArrayList<String> opcoes;
private String respostaCorreta;
private String dificuldade;
protected int pontosPergunta;
public Pergunta(String area, String pergunta, ArrayList<String> opcoes, String respostaCorreta, String dificuldade, int pontosPergunta) {
this.area = area;
this.pergunta = pergunta;
this.opcoes = opcoes;
this.respostaCorreta = respostaCorreta;
this.dificuldade = dificuldade;
this.pontosPergunta = pontosPergunta;
}
public static Pergunta readFromFile(String filename) {
try (BufferedReader br = new BufferedReader(new FileReader(filename))) {
String line;
while ((line = br.readLine()) != null) {
String[] parts = line.split("-");
String area = parts[0];
String dificuldade = parts[1];
String pergunta = parts[2];
ArrayList<String> opcoes = new ArrayList<>(Arrays.asList(parts[3].split(",")));
String respostaCorreta = parts[4];
int pontosPergunta = Integer.parseInt(parts[5]);
return new Pergunta(area, pergunta, opcoes, respostaCorreta, dificuldade, pontosPergunta);
}
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
public String getPergunta() {
return pergunta;
}
public ArrayList<String> getOpcoes() {
return opcoes;
}
public void setArea(String area){
this.area=area;
}
public String getArea(){
return this.area;
}
public class PerguntaArtes extends Pergunta {
public PerguntaArtes(String area, String pergunta, ArrayList<String> opcoes, String respostaCorreta, String dificuldade, int pontosPergunta) {
super(area, pergunta, opcoes, respostaCorreta, dificuldade, pontosPergunta);
}
public int calcularPontuacao(){
return pontosPergunta * 10;
}
}
以下方法是检查我的答案是否正确，我需要它从子类调用该方法
private void checkAnswer(String selectedOption, String respostaCorreta, Pergunta pergunta){
if (selectedOption.equals(respostaCorreta)){
if (pergunta.getArea().equals("PerguntaArtes")){
PerguntaArtes PerguntaArtes = (PerguntaArtes) pergunta;
score += PerguntaArtes.calcularPontuacao();
}
if (pergunta.getArea().equals("PerguntaCiencias")){
score += 20;
}
if (pergunta.getArea().equals("PerguntaDesporto")){
score += 20;
}
questionnumber += 1;
if (questionnumber <= 5){
displayQuestion(questionnumber);
}
else {
endGame();
}
}
else {
questionnumber += 1;
if (questionnumber <= 5){
displayQuestion(questionnumber);
}
else {
endGame();
}
}
}
在这种情况下，它给了我以下错误：
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: class Pergunta cannot be cast to class PerguntaArtes (Pergunta and PerguntaArtes are in unnamed module of loader 'app')
at Screen.checkAnswer(Screen.java:164)
at Screen$2.actionPerformed(Screen.java:142)
at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1972)
at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2313)
at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279)
at java.desktop/java.awt.Component.processMouseEvent(Component.java:6626)
at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3389)
at java.desktop/java.awt.Component.processEvent(Component.java:6391)
at java.desktop/java.awt.Container.processEvent(Container.java:2266)
at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5001)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2324)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4833)
at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4948)
at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4575)
at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4516)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2310)
at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2780)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4833)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:775)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:720)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:714)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:97)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:747)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:744)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
我也尝试过其他方法，但没有找到解决办法。 我也不能使用instanceof或class.getName()，因为如果我使用它我就会受到惩罚。 你们能帮我吗？
您可以：
public abstract class Pergunta {
public abstract int calcularPontuacao();
}
然后在你的子方法上重写它
public class PerguntaArtes extends Pergunta{
@Override
public int calcularPontuacao() {
return pontosPergunta * 10;
}
}
public class PerguntaScience extends Pergunta{
@Override
public int calcularPontuacao() {
return pontosPergunta * 20;
}
}
public interface PuntuationRegister {
int calcularPontucao();
}
public class PerguntaArtes implements PuntuationRegister{
@Override
public int calcularPontuacao() {
return pontosPergunta * 10;
}
}
我还建议您在这部分使用 .equalsIgnoreCase 或枚举
if (pergunta.getArea().equals("PerguntaArtes"))