SpringMVC结合模板模式实现MyBatisPlus传递嵌套JSON数据

 
public class JsonArrayHandler<T> extends BaseTypeHandler<List<T>> {
 
    private Class<T> type;
 
    public JsonArrayHandler() {
        // 添加无参构造函数
    }
    public JsonArrayHandler(Class<T> type) {
        if (type == null) {
            throw new IllegalArgumentException("Type argument cannot be null");
        }
        this.type = type;
    }
 
    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, List<T> parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, JSONArray.toJSONString(parameter));
    }
 
    @Override
    public List<T> getNullableResult(ResultSet rs, String columnName) throws SQLException {
        String json = rs.getString(columnName);
        return parseJsonArray(json);
    }
 
    @Override
    public List<T> getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        String json = rs.getString(columnIndex);
        return parseJsonArray(json);
    }
 
    @Override
    public List<T> getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        String json = cs.getString(columnIndex);
        return parseJsonArray(json);
    }
 
    private List<T> parseJsonArray(String json) {
        JSONArray jsonArray = JSONArray.parseArray(json);
        return jsonArray.toJavaList(type);
    }
}

public class CategoryHandler extends JsonArrayHandler<Category> {
    public CategoryHandler() {
        super(Category.class);
    }
}

public class RoleHandler extends JsonArrayHandler<Role> {
    public RoleHandler() {
        super(Role.class);
    }
}

public class OrderItemHandler extends JsonArrayHandler<OrderItem> {
    public OrderItemHandler() {
        super(OrderItem.class);
    }
}

public class ImageHandler extends JsonArrayHandler<String> {
    public ImageHandler() {
        super(String.class);
    }
}

public class TagHandler extends JsonArrayHandler<Tag> {
    public TagHandler() {
        super(Tag.class);
    }
}

public AnswerHandler(Class<Answer> type) {
    super(Answer.class);
}

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
@TableName("tb_questionnaire")
public class Questionnaire {
    /**
    * 主键
     */
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;
    private int qid;
 
    private String answer;
    private String qname;
    private String question;
    private String tab;
    @TableField(exist = false,typeHandler = AnswerHandler.class)
    private List<Answer> ans;
 
    public void setAnswer() {
        this.answer = JSONUtil.toJsonStr(ans);
    }
    public void setAnswerList() {
        this.ans = JSONUtil.toList(answer,Answer.class);
        answer=null;
    }
}