如何读取excel文件并将其转换为java抽象类？

Question

我正在开发一个web应用程序，我必须完成的任务之一是添加一个excel导入功能，该功能将读取xlsx文件并将其转换为抽象类列表

将它转换为一个类很容易，有很多关于如何实现它的教程，但没有一个关于抽象类的教程

抽象类称为AbstractQuestion，它表示一个问题，有多种类型的问题，如单选题、多选题和文本问题

基本上，excel文件的每一行都可以是不同类型的问题，我需要在最后返回一个AbstractQuestion列表。此外，多项选择题和单项选择题最多可以有10个选项

问题:

@SuppressWarnings("serial")
@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "question_type", discriminatorType = 
DiscriminatorType.STRING)
public abstract class AbstractQuestion implements Serializable{

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;

@Column(name="code", nullable=false)
private String code;

@Column(name="question", nullable=false)
private String question;

@Version
private long version;

private @OneToMany(mappedBy="question")
List<AbstractAnswer> answers = new ArrayList<AbstractAnswer>();

public AbstractAnswer currentUserAnswer;

public AbstractQuestion() {
    super();
    // TODO Auto-generated constructor stub
}



public long getId() {
    return id;
}



public void setId(long id) {
    this.id = id;
}



public String getCode() {
    return code;
}



public void setCode(String code) {
    this.code = code;
}



public String getQuestion() {
    return question;
}



public void setQuestion(String question) {
    this.question = question;
}


public long getVersion() {
    return version;
}



public void setVersion(long version) {
    this.version = version;
}



public List<AbstractAnswer> getAnswers() {
    return answers;
}



public void setAnswers(List<AbstractAnswer> answers) {
    this.answers = answers;
}

public void putCurrentUserAnswer(AbstractAnswer answer) {
    this.currentUserAnswer = answer; 
}

public abstract void accept(QuestionVisitor q);
public abstract AbstractAnswer createAnswer(User user);



}

文本问题：

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(discriminatorType = DiscriminatorType.STRING)
@DiscriminatorValue("Text")
public class TextQuestion extends AbstractQuestion {

public TextQuestion() {
    super();
}

@Override
public void accept(QuestionVisitor q) {
    q.process(this);

}

public String getType() {
    return QuestionUtility.TEXT_QUESTION;
}

@Override
public AbstractAnswer createAnswer(User user) {
    TextAnswer answer = new TextAnswer();
    answer.setAnswerer(user);
    answer.setQuestion(this);
    answer.setId(0);
    answer.setVersion(0);
    answer.setAnswered(false);
    return answer;
}
}

单选题：

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(discriminatorType = DiscriminatorType.STRING)
@DiscriminatorValue("SingleChoice")
public class SingleChoiceQuestion extends AbstractQuestion {

@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
@JoinTable(name = "singlechoice_options", joinColumns = {
        @JoinColumn(name= "parent" )
    },inverseJoinColumns = {
        @JoinColumn(name = "child")
    }
)
private List<Option> options = new ArrayList<Option>();



public SingleChoiceQuestion() {
    super();
    // TODO Auto-generated constructor stub
}

@Override
public void accept(QuestionVisitor q) {
    q.process(this);

}

public String getType() {
    return QuestionUtility.SINGLE_CHOICE_QUESTION;
}



public List<Option> getOptions() {
    return options;
}

public void setOptions(List<Option> options) {
    this.options = options;
}


@Override
public AbstractAnswer createAnswer(User user) {
    SingleChoiceAnswer answer = new SingleChoiceAnswer();
    answer.setAnswerer(user);
    answer.setQuestion(this);
    answer.setId(0);
    answer.setVersion(0);
    answer.setAnswered(false);
    return answer;
}
}

多项选择题：

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(discriminatorType = DiscriminatorType.STRING)
@DiscriminatorValue("MultipleChoice")
public class MultipleChoiceQuestion extends AbstractQuestion {

@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.MERGE)
@JoinTable(name = "multiplechoice_options", joinColumns = {
        @JoinColumn(name= "parent" )
    },inverseJoinColumns = {
        @JoinColumn(name = "child")
    }
)
private List<Option> options = new ArrayList<Option>();


public MultipleChoiceQuestion() {
    super();
    // TODO Auto-generated constructor stub
}

@Override
public void accept(QuestionVisitor q) {
    q.process(this);

}

public String getType() {
    return QuestionUtility.MULTIPLE_CHOICE_QUESTION;
}



public List<Option> getOptions() {
    return options;
}

public void setOptions(List<Option> options) {
    this.options = options;
}


@Override
public AbstractAnswer createAnswer(User user) {
    MultipleChoiceAnswer answer = new MultipleChoiceAnswer();
    answer.setAnswerer(user);
    answer.setQuestion(this);
    answer.setId(0);
    answer.setVersion(0);
    answer.setAnswered(false);
    return answer;
}
}

选项：

@SuppressWarnings("serial")
@Entity
@Table(name = "option")
public class Option implements Serializable{

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;

@Column(name = "option", nullable=false)
private String option;

@Column(name = "weight", nullable=false)
private int weight;

@Version
private int version;

public Option() {
    super();
    // TODO Auto-generated constructor stub
}

public long getId() {
    return id;
}

public void setId(long id) {
    this.id = id;
}

public String getOption() {
    return option;
}

public void setOption(String option) {
    this.option = option;
}


public int getWeight() {
    return weight;
}

public void setWeight(int weight) {
    this.weight = weight;
}

public int getVersion() {
    return version;
}

public void setVersion(int version) {
    this.version = version;
}
}

然后让我们想象一下这个excel文件： xlsx file

目标是返回一个抽象问题列表。有可能吗？如果是，我怎么做？任何可能的解决办法都将不胜感激

谢谢你