Refactor/value object

src/main/java/se/citerus/dddsample/application/impl/BookingServiceImpl.java

@@ -41,7 +41,7 @@ public TrackingId bookNewCargo(final UnLocode originUnLocode,
     Cargo cargo = cargoFactory.createCargo(originUnLocode, destinationUnLocode, arrivalDeadline);
 
     cargoRepository.store(cargo);
-    logger.info("Booked new cargo with tracking id {}", cargo.trackingId().idString());
+    logger.info("Booked new cargo with tracking id {}", cargo.trackingId().id());
 
     return cargo.trackingId();
   }

src/main/java/se/citerus/dddsample/domain/model/cargo/Cargo.java

@@ -73,7 +73,7 @@ public Cargo(final TrackingId trackingId, final RouteSpecification routeSpecific
     Objects.requireNonNull(trackingId, "Tracking ID is required");
     Objects.requireNonNull(routeSpecification, "Route specification is required");
 
-    this.trackingId = trackingId.idString();
+    this.trackingId = trackingId.id();
     // Cargo origin never changes, even if the route specification changes.
     // However, at creation, cargo origin can be derived from the initial route specification.
     this.origin = routeSpecification.origin();
@@ -87,7 +87,7 @@ public Cargo(final TrackingId trackingId, final RouteSpecification routeSpecific
   public Cargo(TrackingId trackingId, RouteSpecification routeSpecification, Itinerary itinerary) {
     Objects.requireNonNull(trackingId, "Tracking ID is required");
     Objects.requireNonNull(routeSpecification, "Route specification is required");
-    this.trackingId = trackingId.idString();
+    this.trackingId = trackingId.id();
     this.origin = routeSpecification.origin();
     this.routeSpecification = routeSpecification;
     this.itinerary = itinerary.legs();

src/main/java/se/citerus/dddsample/domain/model/cargo/Delivery.java

@@ -303,7 +303,7 @@ private RoutingStatus calculateRoutingStatus(Itinerary itinerary, RouteSpecifica
 
   private boolean calculateUnloadedAtDestination(RouteSpecification routeSpecification) {
     return lastEvent != null &&
-      HandlingEvent.Type.UNLOAD.sameValueAs(lastEvent.type()) &&
+      HandlingEvent.Type.UNLOAD == lastEvent.type() &&
       routeSpecification.destination().sameIdentityAs(lastEvent.location());
   }
 

src/main/java/se/citerus/dddsample/domain/model/cargo/RoutingStatus.java

@@ -1,16 +1,8 @@
 package se.citerus.dddsample.domain.model.cargo;
 
-import se.citerus.dddsample.domain.shared.ValueObject;
-
 /**
  * Routing status. 
  */
-public enum RoutingStatus implements ValueObject<RoutingStatus> {
-  NOT_ROUTED, ROUTED, MISROUTED;
-
-  @Override
-  public boolean sameValueAs(final RoutingStatus other) {
-    return this.equals(other);
-  }
-
+public enum RoutingStatus {
+  NOT_ROUTED, ROUTED, MISROUTED
 }

src/main/java/se/citerus/dddsample/domain/model/cargo/TrackingId.java

@@ -1,62 +1,18 @@
 package se.citerus.dddsample.domain.model.cargo;
 
 import org.apache.commons.lang3.Validate;
-import se.citerus.dddsample.domain.shared.ValueObject;
 
 import java.util.Objects;
 
 /**
  * Uniquely identifies a particular cargo. Automatically generated by the application.
  *  
  */
-public final class TrackingId implements ValueObject<TrackingId> {
+public record TrackingId(String id) {
 
-  private String id;
-
-  /**
-   * Constructor.
-   *
-   * @param id Id string.
-   */
-  public TrackingId(final String id) {
+  public TrackingId {
     Objects.requireNonNull(id);
     Validate.notEmpty(id);
-    this.id = id;
-  }
-
-  /**
-   * @return String representation of this tracking id.
-   */
-  public String idString() {
-    return id;
-  }
-
-  @Override
-  public boolean equals(Object o) {
-    if (this == o) return true;
-    if (o == null || getClass() != o.getClass()) return false;
-
-    TrackingId other = (TrackingId) o;
-
-    return sameValueAs(other);
   }
 
-  @Override
-  public int hashCode() {
-    return id.hashCode();
-  }
-
-  @Override
-  public boolean sameValueAs(TrackingId other) {
-    return other != null && this.id.equals(other.id);
-  }
-
-  @Override
-  public String toString() {
-    return id;
-  }
-
-  TrackingId() {
-    // Needed by Hibernate
-  }
 }

src/main/java/se/citerus/dddsample/domain/model/cargo/TransportStatus.java

@@ -1,15 +1,8 @@
 package se.citerus.dddsample.domain.model.cargo;
 
-import se.citerus.dddsample.domain.shared.ValueObject;
-
 /**
  * Represents the different transport statuses for a cargo.
  */
-public enum TransportStatus implements ValueObject<TransportStatus> {
-  NOT_RECEIVED, IN_PORT, ONBOARD_CARRIER, CLAIMED, UNKNOWN;
-
-  @Override
-  public boolean sameValueAs(final TransportStatus other) {
-    return this.equals(other);
-  }
+public enum TransportStatus {
+  NOT_RECEIVED, IN_PORT, ONBOARD_CARRIER, CLAIMED, UNKNOWN
 }

src/main/java/se/citerus/dddsample/domain/model/handling/HandlingEvent.java

@@ -7,7 +7,6 @@
 import se.citerus.dddsample.domain.model.location.Location;
 import se.citerus.dddsample.domain.model.voyage.Voyage;
 import se.citerus.dddsample.domain.shared.DomainEvent;
-import se.citerus.dddsample.domain.shared.ValueObject;
 
 import java.time.Instant;
 import java.util.Objects;
@@ -62,7 +61,7 @@ public final class HandlingEvent implements DomainEvent<HandlingEvent> {
    * Handling event type. Either requires or prohibits a carrier movement
    * association, it's never optional.
    */
-  public enum Type implements ValueObject<Type> {
+  public enum Type {
     LOAD(true),
     UNLOAD(true),
     RECEIVE(false),
@@ -94,11 +93,6 @@ public boolean prohibitsVoyage() {
       return !requiresVoyage();
     }
 
-    @Override
-    public boolean sameValueAs(Type other) {
-      return this.equals(other);
-    }
-
   }
 
   /**

src/main/java/se/citerus/dddsample/domain/model/handling/HandlingHistory.java

@@ -1,21 +1,18 @@
 package se.citerus.dddsample.domain.model.handling;
 
 import se.citerus.dddsample.domain.model.cargo.TrackingId;
-import se.citerus.dddsample.domain.shared.ValueObject;
 
 import java.util.*;
 import java.util.stream.Collectors;
 
 /**
  * The handling history of a cargo.
  */
-public class HandlingHistory implements ValueObject<HandlingHistory> {
-
-    private final List<HandlingEvent> handlingEvents;
+public record HandlingHistory(List<HandlingEvent> handlingEvents) {
 
     public static final HandlingHistory EMPTY = new HandlingHistory(Collections.<HandlingEvent>emptyList());
 
-    public HandlingHistory(Collection<HandlingEvent> handlingEvents) {
+    public HandlingHistory(List<HandlingEvent> handlingEvents) {
         Objects.requireNonNull(handlingEvents, "Handling events are required");
 
         this.handlingEvents = new ArrayList<>(handlingEvents);
@@ -51,30 +48,11 @@ public HandlingEvent mostRecentlyCompletedEvent() {
      */
     public HandlingHistory filterOnCargo(TrackingId trackingId) {
         List<HandlingEvent> events = handlingEvents.stream()
-                .filter(he -> he.cargo().trackingId().sameValueAs(trackingId))
+                .filter(he -> he.cargo().trackingId().equals(trackingId))
                 .collect(Collectors.toList());
         return new HandlingHistory(events);
     }
 
-    @Override
-    public boolean sameValueAs(HandlingHistory other) {
-        return other != null && this.handlingEvents.equals(other.handlingEvents);
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        final HandlingHistory other = (HandlingHistory) o;
-        return sameValueAs(other);
-    }
-
-    @Override
-    public int hashCode() {
-        return handlingEvents.hashCode();
-    }
-
     private static final Comparator<HandlingEvent> BY_COMPLETION_TIME_COMPARATOR =
             Comparator.comparing(HandlingEvent::completionTime);
 

src/main/java/se/citerus/dddsample/domain/model/handling/UnknownCargoException.java

@@ -21,6 +21,6 @@ public UnknownCargoException(final TrackingId trackingId) {
    */            
   @Override
   public String getMessage() {
-    return "No cargo with tracking id " + trackingId.idString() + " exists in the system";
+    return "No cargo with tracking id " + trackingId.id() + " exists in the system";
   }
 }

src/main/java/se/citerus/dddsample/domain/model/handling/UnknownLocationException.java

@@ -12,6 +12,6 @@ public UnknownLocationException(final UnLocode unlocode) {
 
   @Override
   public String getMessage() {
-    return "No location with UN locode " + unlocode.idString() + " exists in the system";
+    return "No location with UN locode " + unlocode.unlocode() + " exists in the system";
   }
 }

src/main/java/se/citerus/dddsample/domain/model/handling/UnknownVoyageException.java

@@ -15,6 +15,6 @@ public UnknownVoyageException(VoyageNumber voyageNumber) {
 
   @Override
   public String getMessage() {
-    return "No voyage with number " + voyageNumber.idString() + " exists in the system";
+    return "No voyage with number " + voyageNumber.number() + " exists in the system";
   }
 }

src/main/java/se/citerus/dddsample/domain/model/location/Location.java

@@ -43,7 +43,7 @@ public Location(final UnLocode unLocode, final String name) {
     Objects.requireNonNull(unLocode);
     Objects.requireNonNull(name);
 
-    this.unlocode = unLocode.idString();
+    this.unlocode = unLocode.unlocode();
     this.name = name;
   }
 

src/main/java/se/citerus/dddsample/domain/model/location/UnLocode.java

@@ -1,72 +1,26 @@
-package se.citerus.dddsample.domain.model.location;
-
-import org.apache.commons.lang3.Validate;
-import se.citerus.dddsample.domain.shared.ValueObject;
-
-import java.util.Objects;
-import java.util.regex.Pattern;
-
-/**
- * United nations location code.
- * 
- * http://www.unece.org/cefact/locode/
- * http://www.unece.org/cefact/locode/DocColumnDescription.htm#LOCODE
- */
-public final class UnLocode implements ValueObject<UnLocode> {
-
-  private String unlocode;
-
-  // Country code is exactly two letters.
-  // Location code is usually three letters, but may contain the numbers 2-9 as well
-  private static final Pattern VALID_PATTERN = Pattern.compile("[a-zA-Z]{2}[a-zA-Z2-9]{3}");
-
-  /**
-   * Constructor.
-   *
-   * @param countryAndLocation Location string.
-   */
-  public UnLocode(final String countryAndLocation) {
-    Objects.requireNonNull(countryAndLocation, "Country and location may not be null");
-    Validate.isTrue(VALID_PATTERN.matcher(countryAndLocation).matches(),
-      countryAndLocation + " is not a valid UN/LOCODE (does not match pattern)");
-
-    this.unlocode = countryAndLocation.toUpperCase();
-  }
-
-  /**
-   * @return country code and location code concatenated, always upper case.
-   */
-  public String idString() {
-    return unlocode;
-  }
-
-  @Override
-  public boolean equals(final Object o) {
-    if (this == o) return true;
-    if (o == null || getClass() != o.getClass()) return false;
-
-    UnLocode other = (UnLocode) o;
-
-    return sameValueAs(other);
-  }
-
-  @Override
-  public int hashCode() {
-    return unlocode.hashCode();
-  }
-
-  @Override
-  public boolean sameValueAs(UnLocode other) {
-    return other != null && this.unlocode.equals(other.unlocode);
-  }
-
-  @Override
-  public String toString() {
-    return idString();
-  }
-
-  UnLocode() {
-    // Needed by Hibernate
-  }
-
-}
+package se.citerus.dddsample.domain.model.location;
+
+import org.apache.commons.lang3.Validate;
+
+import java.util.Objects;
+import java.util.regex.Pattern;
+
+/**
+ * United nations location code.
+ * 
+ * http://www.unece.org/cefact/locode/
+ * http://www.unece.org/cefact/locode/DocColumnDescription.htm#LOCODE
+ */
+public record UnLocode(String unlocode) {
+
+  private static final Pattern VALID_PATTERN = Pattern.compile("[a-zA-Z]{2}[a-zA-Z2-9]{3}");
+
+  public UnLocode(String unlocode) {
+    Objects.requireNonNull(unlocode, "Country and location may not be null");
+    Validate.isTrue(VALID_PATTERN.matcher(unlocode).matches(),
+            unlocode + " is not a valid UN/LOCODE (does not match pattern)");
+
+    this.unlocode = unlocode.toUpperCase();
+  }
+
+}