How to serialize Joda DateTime with Jackson JSON processor?

This has become very easy with Jackson 2.0 and the Joda module.

ObjectMapper mapper = new ObjectMapper();mapper.registerModule(new JodaModule());

Maven dependency:

<dependency>  <groupId>com.fasterxml.jackson.datatype</groupId>  <artifactId>jackson-datatype-joda</artifactId>  <version>2.1.1</version></dependency>  

Code and documentation:https://github.com/FasterXML/jackson-datatype-joda

Binaries:http://repo1.maven.org/maven2/com/fasterxml/jackson/datatype/jackson-datatype-joda/

In the object you're mapping:

@JsonSerialize(using = CustomDateSerializer.class)public DateTime getDate() { ... }

In CustomDateSerializer:

public class CustomDateSerializer extends JsonSerializer<DateTime> {    private static DateTimeFormatter formatter =         DateTimeFormat.forPattern("dd-MM-yyyy");    @Override    public void serialize(DateTime value, JsonGenerator gen,                           SerializerProvider arg2)        throws IOException, JsonProcessingException {        gen.writeString(formatter.print(value));    }}

As @Kimble has said, with Jackson 2, using the default formatting is very easy; simply register JodaModule on your ObjectMapper.

ObjectMapper mapper = new ObjectMapper();mapper.registerModule(new JodaModule());

For custom serialization/de-serialization of DateTime, you need to implement your own StdScalarSerializer and StdScalarDeserializer; it's pretty convoluted, but anyway.

For example, here's a DateTime serializer that uses the ISODateFormat with the UTC time zone:

public class DateTimeSerializer extends StdScalarSerializer<DateTime> {    public DateTimeSerializer() {        super(DateTime.class);    }    @Override    public void serialize(DateTime dateTime,                          JsonGenerator jsonGenerator,                          SerializerProvider provider) throws IOException, JsonGenerationException {        String dateTimeAsString = ISODateTimeFormat.withZoneUTC().print(dateTime);        jsonGenerator.writeString(dateTimeAsString);    }}

And the corresponding de-serializer:

public class DateTimeDesrializer extends StdScalarDeserializer<DateTime> {    public DateTimeDesrializer() {        super(DateTime.class);    }    @Override    public DateTime deserialize(JsonParser jsonParser,                                DeserializationContext deserializationContext) throws IOException, JsonProcessingException {        try {            JsonToken currentToken = jsonParser.getCurrentToken();            if (currentToken == JsonToken.VALUE_STRING) {                String dateTimeAsString = jsonParser.getText().trim();                return ISODateTimeFormat.withZoneUTC().parseDateTime(dateTimeAsString);            }        } finally {            throw deserializationContext.mappingException(getValueClass());        }    }

Then tie these together with a module:

public class DateTimeModule extends SimpleModule {    public DateTimeModule() {        super();        addSerializer(DateTime.class, new DateTimeSerializer());        addDeserializer(DateTime.class, new DateTimeDeserializer());    }}

Then register the module on your ObjectMapper:

ObjectMapper mapper = new ObjectMapper();mapper.registerModule(new DateTimeModule());