如何为包含日期和数据的有序对的JSON响应创建POJO？

import com.fasterxml.jackson.annotation.JsonFormat;

public class DataItem {
    @JsonFormat(pattern = "yyyy-MM-dd")
    private Date date;
    private String data;

    public DataItem() {
        // 无参构造函数
    }

    public DataItem(Date date, String data) {
        this.date = date;
        this.data = data;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    public String getData() {
        return data;
    }

    public void setData(String data) {
        this.data = data;
    }

    @Override
    public String toString() {
        return "DataItem{" +
                "date=" + date +
                ", data='" + data + '\'' +
                '}';
    }
}