Jackson将日期-时间字符串反序列化为long？

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class DateTimeDeserializer extends JsonDeserializer<Long> {
    private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    @Override
    public Long deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
        String dateString = jsonParser.getText();
        try {
            Date date = DATE_FORMAT.parse(dateString);
            return date.getTime();
        } catch (ParseException e) {
            throw new IOException("Failed to parse date: " + dateString, e);
        }
    }
}

public class Main {
    public static void main(String[] args) throws IOException {
        ObjectMapper objectMapper = new ObjectMapper();
        SimpleModule module = new SimpleModule();
        module.addDeserializer(Long.class, new DateTimeDeserializer());
        objectMapper.registerModule(module);

        String json = "{\"timestamp\":\"2022-01-01 12:00:00\"}";
        MyObject myObject = objectMapper.readValue(json, MyObject.class);
        System.out.println(myObject.getTimestamp()); // 输出：1641024000000
    }
}

public class MyObject {
    private Long timestamp;

    public Long getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(Long timestamp) {
        this.timestamp = timestamp;
    }
}