Implemented story 1 and missing utils

src/main/java/de/etecture/ga/model/Appointment.java

@@ -1,15 +1,14 @@
 package de.etecture.ga.model;
 
 import java.time.Duration;
-import java.time.Instant;
 import java.time.LocalDateTime;
-import java.time.ZoneId;
 import java.util.Date;
 
 import org.springframework.data.annotation.Id;
 import org.springframework.data.jdbc.core.mapping.AggregateReference;
 import org.springframework.data.relational.core.mapping.Column;
 
+import de.etecture.ga.util.DateTimeUtil;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 import lombok.experimental.Accessors;
@@ -17,46 +16,48 @@ import lombok.experimental.Accessors;
 @Data
 @Accessors(fluent = true, chain = true)
 @EqualsAndHashCode(onlyExplicitlyIncluded = true)
-public class Appointment implements Comparable<Appointment>{
+public class Appointment implements Comparable<Appointment> {
 
 	@Id
 	@EqualsAndHashCode.Include
 	private Long id;
-	
+
 	@Column("GARAGE_ID")
 	private AggregateReference<Garage, Long> garageId;
-	
+
 	@Column("SERVICE_ID")
 	private AggregateReference<MDService, Long> serviceId;
-	
+
 	@EqualsAndHashCode.Include
 	private String serviceCode;
-	
+
 	private String serviceName;
-	
+
 	@EqualsAndHashCode.Include
 	private Date appointmentTime;
-	
+
 	@EqualsAndHashCode.Include
 	private Integer slot = 1;
-	
+
 	private Duration duration = Duration.ZERO;
-	
-	
+
 	public LocalDateTime appointmentStart() {
-		return Instant.ofEpochMilli(this.appointmentTime().getTime())
-				.atZone(ZoneId.systemDefault()).toLocalDateTime();
+		if (this.appointmentTime == null)
+			return null;
+		return DateTimeUtil.toLocalDateTime(this.appointmentTime);
 	}
-	
+
 	public LocalDateTime appointmentEnd() {
+		if (this.appointmentTime == null)
+			return null;
 		return this.appointmentStart().plus(this.duration());
 	}
 
-	
 	@Override
 	public int compareTo(Appointment o) {
-		if(o == null || o.appointmentTime() == null) return 1;
-		
+		if (o == null || o.appointmentTime() == null)
+			return 1;
+
 		return this.appointmentTime().compareTo(o.appointmentTime());
 	}
 }