BAEL-2729 code samples for the article (#12443)

* BAEL-2729 code samples for the article

* BAEL-2729 fix formatting issues.

Co-authored-by: Yavuz Tas <ytas@vwd.com>

persistence-modules/spring-data-rest-2/src/main/java/com/baeldung/serializeentityid/Person.java

@@ -0,0 +1,31 @@
+package com.baeldung.serializeentityid;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public class Person {
+
+    /**
+     * This doesn't work without a projection
+     */
+    //@JsonProperty
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    private String name;
+
+    public Long getId() {
+        return this.id;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return this.name;
+    }
+}

persistence-modules/spring-data-rest-2/src/main/java/com/baeldung/serializeentityid/PersonController.java

@@ -0,0 +1,27 @@
+package com.baeldung.serializeentityid;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.rest.webmvc.RepositoryRestController;
+import org.springframework.data.web.PagedResourcesAssembler;
+import org.springframework.hateoas.EntityModel;
+import org.springframework.hateoas.PagedModel;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+
+@RepositoryRestController
+public class PersonController {
+
+    @Autowired
+    PersonRepository repository;
+
+    @GetMapping("/persons")
+    ResponseEntity<?> persons(PagedResourcesAssembler resourcesAssembler) {
+        Page<Person> persons = this.repository.findAll(Pageable.ofSize(20));
+        Page<PersonDto> personDtos = persons.map(PersonDto::new);
+        PagedModel<EntityModel<PersonDto>> pagedModel = resourcesAssembler.toModel(personDtos);
+        return ResponseEntity.ok(pagedModel);
+    }
+
+}

persistence-modules/spring-data-rest-2/src/main/java/com/baeldung/serializeentityid/PersonDto.java

@@ -0,0 +1,21 @@
+package com.baeldung.serializeentityid;
+
+public class PersonDto {
+
+    private final Long id;
+
+    private final String name;
+
+    public PersonDto(Person person) {
+        this.id = person.getId();
+        this.name = person.getName();
+    }
+
+    public Long getId() {
+        return this.id;
+    }
+
+    public String getName() {
+        return this.name;
+    }
+}

persistence-modules/spring-data-rest-2/src/main/java/com/baeldung/serializeentityid/PersonRepository.java

@@ -0,0 +1,7 @@
+package com.baeldung.serializeentityid;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PersonRepository extends JpaRepository<Person, Long> {
+
+}

persistence-modules/spring-data-rest-2/src/main/java/com/baeldung/serializeentityid/PersonView.java

@@ -0,0 +1,15 @@
+package com.baeldung.serializeentityid;
+
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import org.springframework.data.rest.core.config.Projection;
+
+@JsonPropertyOrder({ "id", "name" })
+@Projection(name = "person-view", types = Person.class)
+public interface PersonView {
+
+    Long getId();
+
+    String getName();
+
+}

persistence-modules/spring-data-rest-2/src/main/java/com/baeldung/serializeentityid/RestConfiguration.java

@@ -0,0 +1,27 @@
+package com.baeldung.serializeentityid;
+
+import javax.persistence.EntityManager;
+import javax.persistence.metamodel.Type;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.rest.core.config.RepositoryRestConfiguration;
+import org.springframework.data.rest.webmvc.config.RepositoryRestConfigurer;
+import org.springframework.web.servlet.config.annotation.CorsRegistry;
+
+@Configuration
+public class RestConfiguration implements RepositoryRestConfigurer {
+
+    @Autowired
+    private EntityManager entityManager;
+
+    @Override
+    public void configureRepositoryRestConfiguration(RepositoryRestConfiguration config, CorsRegistry cors) {
+        final Class<?>[] classes = this.entityManager.getMetamodel()
+            .getEntities()
+            .stream()
+            .map(Type::getJavaType)
+            .toArray(Class[]::new);
+        config.exposeIdsFor(classes);
+    }
+}

persistence-modules/spring-data-rest-2/src/main/java/com/baeldung/serializeentityid/SerializeEntityIdApp.java

@@ -0,0 +1,32 @@
+package com.baeldung.serializeentityid;
+
+import javax.annotation.PostConstruct;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SerializeEntityIdApp {
+
+    private final PersonRepository repository;
+
+    public SerializeEntityIdApp(PersonRepository repository) {
+        this.repository = repository;
+    }
+
+    @PostConstruct
+    void onStart() {
+        final Person person1 = new Person();
+        person1.setName("John Doe");
+        final Person person2 = new Person();
+        person2.setName("Markus Boe");
+
+        this.repository.save(person1);
+        this.repository.save(person2);
+    }
+
+    public static void main(String[] args) {
+        SpringApplication.run(SerializeEntityIdApp.class, args);
+    }
+
+}