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我在这里使用接口时遇到问题。当我尝试设置列表中的“答案”到一个ArrayList我得到的错误:使用列表接口,其中给出的类型是要通过setter方法实现的接口
的方法setAnswers(列表)在类型QuestionImpl不适用于参数(ArrayList的)
对我来说,似乎我想在这种情况下使用接口,以便稍后可以指定实现。
public class QuestionImpl extends QuestionAnswerImpl implements Comparable<Object>, Question {
private List<Answer> answers;
public QuestionImpl(){
setAnswers(new ArrayList<AnswerImpl>());
}
@Override
public void setAnswers(List<Answer> answers) {
this.answers = answers;
}
@Override
public List<Answer> getAnswers() {
// TODO Auto-generated method stub
return answers;
}
答接口:
public interface Answer {
int i=0;
public int compareTo(Object object1);
public String getListValu(int question);
public void setNum(int i);
}
Answer class info (most of the code is irrelevant here)
public class AnswerImpl extends QuestionAnswerImpl implements
Comparable<Object>, Answer {...}
变化'setAnswers(新的ArrayList());'(所以''而非'') –