adam bien's blog

To serialize a POJO with JSON-B from Java EE 8 containing a java.time.LocalDate, you can either use the default format, or specify the serialization format with @JsonbDateFormat annotation:

import java.time.LocalDate;
import javax.json.bind.annotation.JsonbCreator;
import javax.json.bind.annotation.JsonbDateFormat;
import javax.json.bind.annotation.JsonbProperty;

public class Developer {

    public LocalDateTime birthdate;

    @JsonbDateFormat(value = "yyyy-MM-dd")
    public LocalDate firstHack;

    @JsonbCreator
    public Developer(
            @JsonbProperty("birthdate") LocalDateTime birthdate, 
            @JsonbProperty("firstHack") LocalDate firstHack) {
        this.birthdate = birthdate;
        this.firstHack = firstHack;
    }
}

Now the Developer can be serialized and deserialized with a javax.json.bind.Jsonb instance:

import java.time.LocalDate;
import java.time.Month;
import javax.json.bind.Jsonb;
import javax.json.bind.JsonbBuilder;

public class DateSerializationTest {
    
    private Jsonb jsonb;
    
    @Before
    public void init() {
        this.jsonb = JsonbBuilder.
        newBuilder().
        build();
    }

    @Test
    public void serialize() {
        Developer developer = new Developer(LocalDateTime.of(1995, Month.MARCH, 12, 12, 42), 
                LocalDate.of(1998, Month.MARCH, 12));
        String serialized = this.jsonb.toJson(developer);
        System.out.println("serialized = " + serialized);
        assertThat(serialized, containsString("birthdate"));

    }

    @Test
    public void deserialize() {
        String deserialzed = " {\"birthdate\":\"1995-03-12T12:42:00\",\"firstHack\":\"1998-03-12\"}";
        Developer duke = this.jsonb.fromJson(deserialzed, Developer.class);
        assertThat(duke.birthdate.getYear(), is(1995));
    }

}

To run the example as JUnit test, you will need the following dependencies:

<dependency>
    <groupId>org.glassfish</groupId>
    <artifactId>javax.json</artifactId>
    <version>1.1</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>org.eclipse</groupId>
    <artifactId>yasson</artifactId>
    <version>1.0</version>
    <scope>runtime</scope>
</dependency>

See you at Java EE Workshops at Munich Airport, Terminal 2 or Virtual Dedicated Workshops / consulting. Is Munich's airport too far? Learn from home: airhacks.io.