added functionality to get and update a pet

pom.xml

@@ -152,6 +152,19 @@
       <artifactId>jakarta.xml.bind-api</artifactId>
     </dependency>
 
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+      <scope>provided</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-hateoas</artifactId>
+    </dependency>
   </dependencies>
 
   <build>

src/main/java/org/springframework/samples/petclinic/owner/NewPet.java

@@ -0,0 +1,101 @@
+package org.springframework.samples.petclinic.owner;
+
+import jakarta.annotation.Nonnull;
+import jakarta.persistence.*;
+import jakarta.validation.constraints.NotNull;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.Date;
+
+@Entity
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+
+/**
+ * Simple business object representing a pet.
+ *
+ * @author Shreyas Prayag
+ */
+
+public class NewPet {
+
+	/**
+	 * The unique identifier for the pet. This field is mapped to the "id" column in the
+	 * "new_pet" table. It is automatically generated by the database when a new pet is
+	 * created.
+	 */
+	@Id
+	@GeneratedValue(strategy = GenerationType.IDENTITY)
+	private int id;
+
+	/**
+	 * The name of the pet. This field is mapped to the "name" column in the "new_pet"
+	 * table. It cannot be null and should not be empty.
+	 */
+	@NotNull
+	private String name;
+
+	/**
+	 * The date of birth of the pet. This field is mapped to the "birth_date" column in
+	 * the "new_pet" table. It cannot be null and should not be empty.
+	 */
+	private Date birthDate;
+
+	/**
+	 * The owner of the pet.
+	 * <p>
+	 * This field represents a many-to-one relationship between pets and their owners —
+	 * each pet is associated with one owner, but an owner can have multiple pets.
+	 * </p>
+	 * <p>
+	 * The relationship is mapped via the {@code owner_id} foreign key in the
+	 * {@code new_pet} table.
+	 * </p>
+	 *
+	 * @see Owner
+	 */
+	@ManyToOne
+	@JoinColumn(name = "owner_id")
+	private Owner owner;
+
+	/**
+	 * The temperament of the pet.
+	 * <p>
+	 * This field represents a many-to-one relationship between pets and their
+	 * temperaments — each pet has one temperament, there can be more than one pets with
+	 * one temperament.
+	 * </p>
+	 * <p>
+	 * The relationship is mapped via the {@code temperament_id} foreign key in the
+	 * {@code new_pet} table.
+	 * </p>
+	 *
+	 * @see PetTemperament
+	 */
+	@ManyToOne()
+	@JoinColumn(name = "temperament_id")
+	private PetTemperament temperament;
+
+	/**
+	 * The type of the pet.
+	 * <p>
+	 * This field represents a many-to-one relationship between pets and their owners —
+	 * each pet is associated with one type, but there can be multiple pets of a type.
+	 * </p>
+	 * <p>
+	 * The relationship is mapped via the {@code type_id} foreign key in the
+	 * {@code new_pet} table.
+	 * </p>
+	 *
+	 * @see Owner
+	 */
+	@ManyToOne
+	@JoinColumn(name = "type_id")
+	private PetType type;
+
+}

src/main/java/org/springframework/samples/petclinic/owner/NewPetController.java

@@ -0,0 +1,92 @@
+package org.springframework.samples.petclinic.owner;
+
+import org.springframework.hateoas.EntityModel;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.linkTo;
+import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.methodOn;
+
+/**
+ * new Controller to handle requests relating pet
+ *
+ * The existing controller is not a REST API controller. So this controller is created to
+ * cater Rest endpoints relating Pet.
+ *
+ * @author Shreyas Prayag
+ * @since 1.0
+ */
+@RestController
+@RequestMapping("owners/{ownerId}")
+public class NewPetController {
+
+	private final NewPetRepository petRepository;
+
+	NewPetController(NewPetRepository petRepository) {
+		this.petRepository = petRepository;
+	}
+
+	/**
+	 * Retrieves a pet by its ID.
+	 * <p>
+	 * This endpoint returns a pet based on the provided pet ID. If the pet with the given
+	 * ID exists, it returns the pet details in the response body with a 200 OK status. If
+	 * the pet is not found, a 404 Not Found status is returned.
+	 * </p>
+	 * @param petId The ID of the pet to retrieve. It is expected to be a positive
+	 * integer.
+	 * @return A {@link ResponseEntity} containing the {@link Pet} object if found, or a
+	 * 404 response if not found.
+	 *
+	 * this endpoint is hateoas compliant
+	 */
+	@GetMapping("/pet/{petId}")
+	public ResponseEntity<EntityModel<NewPet>> getPetById(@PathVariable int ownerId, @PathVariable int petId) {
+
+		NewPet pet = petRepository.findById(petId);
+
+		if (pet == null) {
+			return ResponseEntity.notFound().build();
+		}
+
+		EntityModel<NewPet> petResource = EntityModel.of(pet);
+
+		// Add self link
+		petResource.add(linkTo(methodOn(NewPetController.class).getPetById(ownerId, petId)).withSelfRel());
+
+		// Add link to create new pet
+		petResource.add(linkTo(methodOn(NewPetController.class).createNewPet(ownerId, null)).withRel("create-new-pet"));
+
+		return ResponseEntity.ok(petResource);
+
+	}
+
+	/**
+	 * Creates a new pet.
+	 * <p>
+	 * This endpoint accepts a {@link Pet} object in the request body and saves it to the
+	 * database. It returns the created {@link Pet} object along with a 201 Created HTTP
+	 * status code. If the pet data is invalid, a 400 Bad Request status is returned.
+	 * </p>
+	 * @param newPet The pet object to create. This is expected to contain the pet details
+	 * in the request body.
+	 * @return A {@link ResponseEntity} containing the created {@link Pet} object and a
+	 * 201 Created status.
+	 *
+	 * this endpoint is hateoas compliant
+	 */
+	@PostMapping("/pet")
+	public ResponseEntity<EntityModel<NewPet>> createNewPet(@PathVariable int ownerId, @RequestBody NewPet newPet) {
+
+		NewPet savedPet = petRepository.save(newPet);
+		EntityModel<NewPet> petResource = EntityModel.of(savedPet);
+
+		// Add self link
+		petResource.add(linkTo(methodOn(NewPetController.class).getPetById(ownerId, savedPet.getId())).withSelfRel());
+
+		return ResponseEntity.status(HttpStatus.CREATED).body(petResource);
+
+	}
+
+}

src/main/java/org/springframework/samples/petclinic/owner/NewPetRepository.java

@@ -0,0 +1,33 @@
+package org.springframework.samples.petclinic.owner;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+/**
+ * Repository interface for managing {@link NewPet} entities.
+ * <p>
+ * Extends {@link JpaRepository} to provide CRUD operations, pagination, and JPA-specific
+ * functionality.
+ * </p>
+ *
+ * @author You
+ * @since 1.0
+ */
+public interface NewPetRepository extends JpaRepository<NewPet, Integer> {
+
+	/**
+	 * Finds the pet with the given id.
+	 * @param id The id of the pet to search for.
+	 * @return a pet with the specified id.
+	 *
+	 */
+	NewPet findById(int id);
+
+	/**
+	 * Saves the given pet
+	 * @param newPet The pet object to be saved.
+	 * @return pet object being saved.
+	 *
+	 */
+	NewPet save(NewPet newPet);
+
+}

src/main/java/org/springframework/samples/petclinic/owner/PetTemperament.java

@@ -0,0 +1,46 @@
+package org.springframework.samples.petclinic.owner;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.validation.constraints.NotNull;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+
+/**
+ * Simple business object representing pet temperament.
+ *
+ * @author Shreyas Prayag
+ */
+public class PetTemperament {
+
+	/**
+	 * The unique identifier for the temperament. This field is mapped to the "id" column
+	 * in the "pet_temperament" table. It is automatically generated by the database when
+	 * a new temperament is created.
+	 */
+	@Id
+	@GeneratedValue(strategy = GenerationType.IDENTITY)
+	private Integer id;
+
+	/**
+	 * The Temperament of pet. This field is mapped to the "temperament" column in the
+	 * "pet_temperament" table. It cannot be null and should not be empty.
+	 */
+	@NotNull
+	private String temperament;
+
+	public PetTemperament(String temperament) {
+		this.temperament = temperament;
+	}
+
+}

src/main/resources/application.properties

@@ -1,13 +1,23 @@
 # database init, supports mysql too
-database=h2
+database=mysql
 spring.sql.init.schema-locations=classpath*:db/${database}/schema.sql
 spring.sql.init.data-locations=classpath*:db/${database}/data.sql
 
+
+# Data Source properties
+spring.datasource.url=jdbc:mysql://localhost:3306/petclinic
+spring.datasource.username=petclinic
+spring.datasource.password=petclinic
+spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
+
+# Logging level for Hibernate SQL
+logging.level.org.hibernate.SQL=DEBUG
 # Web
 spring.thymeleaf.mode=HTML
 
 # JPA
-spring.jpa.hibernate.ddl-auto=none
+spring.jpa.hibernate.ddl-auto=update
+spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8Dialect
 spring.jpa.open-in-view=false
 
 # Internationalization