Using jsonserialize to realize data type conversion gracefully

One 、

Requirements introduction ： I hope that through annotation , Batch time format In the expected format .

JsonSerialize brief introduction ：com.fasterxml.jackson.databind.annotation Serialization annotation provided by package

What is serialization ：

Encode an object into a byte stream （I/O）; The opposite operation is called deserialization .

The purpose of serialization is to facilitate the transfer of data and storage on disk （ Put one Java Objects are written to the hard disk or transferred to other computers on the network , At this time, we need to convert the object into a byte stream for network transmission . For this kind of general operation , Serialization appears to unify these formats ）

Two 、 actual combat  

1、 First, customize a class inheritance JsonSerializer To rewrite serialize Method , It implements the specific data type conversion logic

@Slf4j
public class DataFormatSerializeer extends JsonSerializer<String> {

  @Override
  public void serialize(String dateStr, JsonGenerator jsonGenerator,
      SerializerProvider serializerProvider) throws IOException {
    if (StringUtils.isNotBlank(dateStr)) {
      SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-mm-dd hh:mm:ss");
      Date date = null;
      try {
        date = dateFormat.parse(dateStr);
        Timestamp time = new Timestamp(date.getTime());
        jsonGenerator.writeString(DateUtils.convertSqlTimeStampToUtc(time, "UTC-4",
            DateUtils.ISO8601_DATE_TIME_FORMAT));
      } catch (ParseException e) {
        log.error("date convert error");
      }
    } else {
      jsonGenerator.writeString("");
    }
  }
}

2. application

  @JsonSerialize(using = DataFormatSerializeer.class)// Here we refer to our custom class 
  private String date;