Java 8 异常：com.fasterxml.jackson.datatype.jsr310.deser.InstantDeserializer 没有默认值

Question

I have a model class that has a field:

 @JsonDeserialize(using = InstantDeserializer.class)
 @JsonFormat(pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSZ")
 private OffsetDateTime offsetDt;

When a request of this model is sent to the server, my controller throws an exception:

Caused by: java.lang.IllegalArgumentException: 
Class com.fasterxml.jackson.datatype.jsr310.deser.InstantDeserializer 
has no default (no arg) constructor

The pom.xml has the dependency of version 2.8.11:

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
</dependency>

I understand that it is caused by @JsonDeserialize requiring no-arg constructor, but is there a workaround?

Answer 1

The error says that you need a class with no arg constructor, so you could extend from InstantDeserializer . (Take as example the code in InstantDeserializer for the arguments of super() )

public class DefaultInstantDeserializer extends InstantDeserializer<OffsetDateTime> {
    public DefaultInstantDeserializer() {
        super(OffsetDateTime.class, DateTimeFormatter.ISO_OFFSET_DATE_TIME,
                OffsetDateTime::from,
                a -> OffsetDateTime.ofInstant(Instant.ofEpochMilli(a.value), a.zoneId),
                a -> OffsetDateTime.ofInstant(Instant.ofEpochSecond(a.integer, a.fraction), a.zoneId),
                (d, z) -> d.withOffsetSameInstant(z.getRules().getOffset(d.toLocalDateTime())),
                true);
    }
}

Then you can use it:

@JsonDeserialize(using = DefaultInstantDeserializer.class)