Converting ZonedDateTime type to Gson

Question

I have rest service that return arraylist of object,and I have implemented jersy restful client to execute it,but I have problem in converting ZonedDateTime type to json so

Answer 1

There are at least two ways to achieve this:

1) Gson with JsonDeserializer

Little changes within your code:

Type listType =  new TypeToken>() {}.getType();
List scorefactors = new GsonBuilder()
            .registerTypeAdapter(ZonedDateTime.class, GsonHelper.ZDT_DESERIALIZER)
            .create()
            .fromJson(output, listType);

Helper Class

class GsonHelper {

    public static final JsonDeserializer ZDT_DESERIALIZER = new JsonDeserializer() {
        @Override
        public ZonedDateTime deserialize(final JsonElement json, final Type typeOfT, final JsonDeserializationContext context) throws JsonParseException {
            JsonPrimitive jsonPrimitive = json.getAsJsonPrimitive();
            try {

                // if provided as String - '2011-12-03T10:15:30+01:00[Europe/Paris]'
                if(jsonPrimitive.isString()){
                    return ZonedDateTime.parse(jsonPrimitive.getAsString(), DateTimeFormatter.ISO_ZONED_DATE_TIME);
                }

                // if provided as Long
                if(jsonPrimitive.isNumber()){
                    return ZonedDateTime.ofInstant(Instant.ofEpochMilli(jsonPrimitive.getAsLong()), ZoneId.systemDefault());
                }

            } catch(RuntimeException e){
                throw new JsonParseException("Unable to parse ZonedDateTime", e);
            }
            throw new JsonParseException("Unable to parse ZonedDateTime");
        }
    };

}

2) Use MessageBodyReader & XMLAdapter

Changes for your Client implementation:

ClientConfig config = new DefaultClientConfig();
config.getFeatures().put(JSONConfiguration.FEATURE_POJO_MAPPING, Boolean.TRUE);
Client client = Client.create(config);

List result = client.resource("http://localhost:8080/adap/api/getScoreFactor"")
                .accept("application/json")
                .get(ClientResponse.class)
                .getEntity(new GenericType>(){});

System.out.println(result);

You might need to import jersey-json for this

    com.sun.jersey
    jersey-bundle
    1.19.1


    com.sun.jersey
    jersey-json
    1.19.1

Btw, why do you use 1.*?

Your Scorefactor

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Scorefactor implements Serializable {

    @Column(name = "lastmodifieddate")
    @XmlElement(name = "lastmodifieddate")
    @XmlJavaTypeAdapter(ZonedDateTimeToStringXmlAdapter.class)
    private ZonedDateTime lastmodifieddate;

    //...

ZonedDateTime from / to String (recommended)

public class ZonedDateTimeToStringXmlAdapter extends XmlAdapter {

    @Override
    public ZonedDateTime unmarshal(final String v) throws DateTimeParseException {
        return ZonedDateTime.parse(v);
    }

    @Override
    public String marshal(final ZonedDateTime v) throws Exception {
        return v.toString();
    }

}

ZonedDateTime from / to Long

public class ZonedDateTimeToLongXmlAdapter extends XmlAdapter {

    @Override
    public ZonedDateTime unmarshal(final Long v) throws DateTimeParseException {
        return ZonedDateTime.ofInstant(Instant.ofEpochMilli(v.longValue()), ZoneId.systemDefault()); 
    }

    @Override
    public Long marshal(final ZonedDateTime v) throws Exception {
        return Long.valueOf(v.toInstant().toEpochMilli());
    }

}

You could also build your own MessageBodyReader/MessageBodyWriter or use other implementations like Moxy.

I would like to recommend to use Jersey 2.*.

Hope this was helpful somehow. Have a nice day.