JSON serialization case summary

1、 @JsonSerialize

@JsonSerialize@JsonSerialize annotation , Mainly used in data conversion , The annotation acts on the of the attribute getter() On the way .

Case a

scene ： id by Long Type , The number is longer than 19 When the bit passes to the front end, it changes its value . Accuracy is lost .
terms of settlement ： take Long Type conversion to String type , Solve the loss of accuracy .

Be careful ： The field to be converted must be of wrapper type , Otherwise, the conversion will fail .

@JsonSerialize(using = ToStringSerializer.class)
private Long parentId;    // Successful transformation 

@JsonSerialize(using = ToStringSerializer.class)
private long parentId;    // Conversion failed 

Case 2

scene ： Two decimal places of the amount shall be reserved , rounding
terms of settlement ： Define methods

    @JsonSerialize(using = CustomDecimalSerialize.class)
    private BigDecimal totalCom;

CustomDecimalSerialize

public class CustomDecimalSerialize extends JsonSerializer<BigDecimal> {
    

    private DecimalFormat df = new DecimalFormat("0.00");

    @Override
    public void serialize(BigDecimal value, JsonGenerator gen, SerializerProvider serializers)
            throws IOException, JsonProcessingException {
    
        if (value != null) {
    
            df.setRoundingMode(RoundingMode.HALF_UP);
            gen.writeString(df.format(value));
        }
    }
}

2、 @JsonProperty

@JsonProperty("xxx") Used on properties , This attribute is recognized as... When serializing and deserializing xxx

	// Serialization will DATA_SOURCE mapping dataSource
    @JsonProperty(value = "DATA_SOURCE")
    private String dataSource;

3、@DateTimeFormat and @JsonFormat

@DateTimeFormat and @JsonFormat

Other links ：

jackson Use @JsonSerialize format BigDecimal solve .00 Don't show problems