Main.java

package net.hamnaberg.json.examples;

import javaslang.collection.List;
import javaslang.control.Option;
import net.hamnaberg.json.Codecs;
import net.hamnaberg.json.DecodeResult;
import net.hamnaberg.json.Json;
import net.hamnaberg.json.JsonCodec;
import net.hamnaberg.json.io.JacksonStreamingParser;

import java.time.LocalDate;

public class Main {
    public static void main(String[] args) {
        Person p1 = new Person("John Doe", Option.some(LocalDate.of(1981, 1, 1)), List.empty());
        System.out.println("p1 = " + p1);
        Json.JValue data = new JacksonStreamingParser().parse(Main.class.getResourceAsStream("/person.json"));
        System.out.println("data = " + data);

        DecodeResult<Person> decodePerson = MyExtractors.person().apply(data.asJsonObjectOrEmpty());
        System.out.println("decodePerson = " + decodePerson);
        DecodeResult<Person> decodePerson2 = MyExtractors.person().decoder().fromJson(data);
        System.out.println("decodePerson2 = " + decodePerson2);
        JsonCodec<LocalDate> localDateJsonCodec = Codecs.StringCodec.tryNarrow(LocalDate::parse, LocalDate::toString);
        JsonCodec<Person> personcodec = Codecs.codec3(PersonIso.INSTANCE, Codecs.StringCodec, Codecs.OptionCodec(localDateJsonCodec), Codecs.listCodec(Codecs.StringCodec)).
                apply("name", "birthDate", "interests");

        DecodeResult<Person> person3 = personcodec.fromJson(data);
        Option<Json.JValue> data2 = personcodec.toJson(person3.unsafeGet());
        System.out.println("data2 = " + data2);
        
        /* Outputs:
        p1 = Person{name='John Doe', birthDate=Some(1981-01-01), interests=List()}
data = JObject{value={name=JString{value='John Doe'}, birthDate=JString{value='1982-01-01'}, interests=JArray{value=List()}}}
decodePerson = Ok(value='Person{name='John Doe', birthDate=Some(1982-01-01), interests=List()}')
decodePerson2 = Ok(value='Person{name='John Doe', birthDate=Some(1982-01-01), interests=List()}')
data2 = Some(JObject{value={name=JString{value='John Doe'}, birthDate=JString{value='1982-01-01'}, interests=JArray{value=List()}}})
        
        */
    }
}

MyExtractors.java

package net.hamnaberg.json.examples;

import net.hamnaberg.json.Codecs;
import net.hamnaberg.json.extract.Extractor;
import net.hamnaberg.json.extract.Extractors;

import java.time.LocalDate;

import static net.hamnaberg.json.extract.TypedField.*;

public class MyExtractors {
    public static Extractor<Person> person() {
        return Extractors.extract3(
                TString("name"),
                TOptional("birthDate", Codecs.StringCodec.map(LocalDate::parse)),
                TJArray("interests").mapToList(j -> j.asString().getOrElse("")),
                Person::new
        );
    }
}

Person.java

package net.hamnaberg.json.examples;

import javaslang.collection.List;
import javaslang.control.Option;

import java.time.LocalDate;

public class Person {
    public final String name;
    public final Option<LocalDate> birthDate;
    public final List<String> interests;

    public Person(String name, Option<LocalDate> birthDate, List<String> interests) {
        this.birthDate = birthDate;
        this.name = name;
        this.interests = interests;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", birthDate=" + birthDate +
                ", interests=" + interests +
                '}';
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Person person = (Person) o;

        if (!name.equals(person.name)) return false;
        if (!birthDate.equals(person.birthDate)) return false;
        return interests.equals(person.interests);

    }

    @Override
    public int hashCode() {
        int result = name.hashCode();
        result = 31 * result + birthDate.hashCode();
        result = 31 * result + interests.hashCode();
        return result;
    }
}

PersonIso.java

package net.hamnaberg.json.examples;

import javaslang.Tuple3;
import javaslang.collection.List;
import javaslang.control.Option;
import net.hamnaberg.json.Iso;

import java.time.LocalDate;

public enum PersonIso implements Iso<Person, Tuple3<String, Option<LocalDate>, List<String>>> {
    INSTANCE;

    @Override
    public Tuple3<String, Option<LocalDate>, List<String>> get(Person person) {
        return new Tuple3<>(person.name, person.birthDate, person.interests);
    }

    @Override
    public Person reverseGet(Tuple3<String, Option<LocalDate>, List<String>> t) {
        return t.transform(Person::new);
    }
}