SpringBoot实现子类的反序列化示例代码

@Data
public class Exam {

 private String name;
 private List questions;
}

@Data
@JsonTypeInfo(
  use = JsonTypeInfo.Id.NAME,
  include = JsonTypeInfo.As.EXISTING_PROPERTY,
  property = "type",
  visible = true)
@JsonSubTypes({
  @JsonSubTypes.Type(value = SingleChoiceQuestion.class, name = Question.SINGLE_CHOICE),
  @JsonSubTypes.Type(value = MultipleChoiceQuestion.class, name = Question.MULTIPLE_CHOICE),
  @JsonSubTypes.Type(value = TrueOrFalseQuestion.class, name = Question.TRUE_OR_FALSE),
})
public abstract class Question {

 protected static final String SINGLE_CHOICE = "single_choice";
 protected static final String MULTIPLE_CHOICE = "multiple_choice";
 protected static final String TRUE_OR_FALSE = "true_or_false";

 protected String type;
 protected String content;
 protected String answer;

 protected boolean isCorrect(String answer) {
  return this.answer.equals(answer);
 }
}

@Data
@EqualsAndHashCode(callSuper = true)
public class TrueOrFalseQuestion extends Question {

  public TrueOrFalseQuestion() {
    this.type = TRUE_OR_FALSE;
  }
}

@Data
@EqualsAndHashCode(callSuper = true)
public abstract class ChoiceQuestion extends Question {

  private List options;

  @Data
  public static class Option {
    private String code;
    private String content;
  }
}

@Data
@EqualsAndHashCode(callSuper = true)
public class SingleChoiceQuestion extends ChoiceQuestion {

  public SingleChoiceQuestion() {
    this.type = SINGLE_CHOICE;
  }
}

@Data
@EqualsAndHashCode(callSuper = true)
public class MultipleChoiceQuestion extends ChoiceQuestion {

  public MultipleChoiceQuestion() {
    this.type = MULTIPLE_CHOICE;
  }

  @Override
  public void setAnswer(String answer) {
    this.answer = sortString(answer);
  }

  @Override
  public boolean isCorrect(String answer) {
    return this.answer.equals(sortString(answer));
  }

  private String sortString(String str) {
    char[] chars = str.toCharArray();
    Arrays.sort(chars);
    return String.valueOf(chars);
  }
}

@RequestMapping(value = "/exam", method = RequestMethod.POST)
public List parseExam(@RequestBody Exam exam) {
  List results = new ArrayList<>();
  results.add(String.format("Parsed an exam, name = %s", exam.getName()));
  results.add(String.format("Exam has %s questions", exam.getQuestions().size())) 
  
  List types = new ArrayList<>();
  for (Question question : exam.getQuestions()) {
    types.add(question.getType());
  }
  results.add(String.format("Questions types: %s", types.toString()));
  return results;
}

curl -X POST \
 http://127.0.0.1:8080/exam/ \
 -H 'Content-Type: application/json' \
 -d '{
  "name":"一场考试",
  "questions": [
    {
      "type": "single_choice",
      "content": "单选题",
      "options": [
        {
          "code":"A",
          "content": "选项A"
        },{
          "code":"B",
          "content": "选项B"
        }],
      "answer": "A"
    },{
      "type": "multiple_choice",
      "content": "多选题",
      "options": [
        {
          "code":"A",
          "content": "选项A"
        },{
          "code":"B",
          "content": "选项B"
        }],
      "answer": "AB"
    },{
      "type": "true_or_false",
      "content": "判断题",
      "answer": "True"
    }]
}'

[
  "Parsed an exam, name = 一场考试",
  "Exam has 3 questions",
  "Questions types: [single_choice, multiple_choice, true_or_false]"
]