[impr-manual-id] manually set id before save() (#18305)

Author: sk1418

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/HibernateUtil.java

@@ -13,6 +13,7 @@
 import org.hibernate.service.ServiceRegistry;
 
 import com.baeldung.hibernate.entities.DeptEmployee;
+import com.baeldung.hibernate.pojo.BaseballPlayer;
 import com.baeldung.hibernate.pojo.Course;
 import com.baeldung.hibernate.pojo.Employee;
 import com.baeldung.hibernate.pojo.EntityDescription;
@@ -25,6 +26,7 @@
 import com.baeldung.hibernate.pojo.Post;
 import com.baeldung.hibernate.pojo.Product;
 import com.baeldung.hibernate.pojo.Student;
+import com.baeldung.hibernate.pojo.TennisPlayer;
 import com.baeldung.hibernate.pojo.TemporalValues;
 import com.baeldung.hibernate.pojo.User;
 import com.baeldung.hibernate.pojo.UserProfile;
@@ -86,6 +88,8 @@ private static SessionFactory makeSessionFactory(ServiceRegistry serviceRegistry
         metadataSources.addAnnotatedClass(DeptEmployee.class);
         metadataSources.addAnnotatedClass(com.baeldung.hibernate.entities.Department.class);
         metadataSources.addAnnotatedClass(Post.class);
+        metadataSources.addAnnotatedClass(TennisPlayer.class);
+        metadataSources.addAnnotatedClass(BaseballPlayer.class);
 
         Metadata metadata = metadataSources.getMetadataBuilder()
                 .build();

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/pojo/BaseballPlayer.java

@@ -0,0 +1,32 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class BaseballPlayer {
+
+    @Id
+    private Long playerId; // Long instead of long
+    private String name;
+
+    public BaseballPlayer(String name) {
+        this.name = name;
+    }
+
+    public Long getPlayerId() {
+        return playerId;
+    }
+
+    public void setPlayerId(Long playerId) {
+        this.playerId = playerId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/pojo/TennisPlayer.java

@@ -0,0 +1,32 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class TennisPlayer {
+
+    @Id
+    private long playerId;
+    private String name;
+
+    public TennisPlayer(String name) {
+        this.name = name;
+    }
+
+    public Long getPlayerId() {
+        return playerId;
+    }
+
+    public void setPlayerId(Long playerId) {
+        this.playerId = playerId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}

persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/IdentifiersIntegrationTest.java

@@ -1,24 +1,30 @@
 package com.baeldung.hibernate;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import java.io.IOException;
+
+import org.hibernate.Session;
+import org.hibernate.Transaction;
+import org.hibernate.id.IdentifierGenerationException;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.hibernate.Transaction;
-import java.io.IOException;
-import org.hibernate.Session;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
-import com.baeldung.hibernate.pojo.Product;
+import com.baeldung.hibernate.pojo.BaseballPlayer;
 import com.baeldung.hibernate.pojo.Course;
 import com.baeldung.hibernate.pojo.OrderEntry;
 import com.baeldung.hibernate.pojo.OrderEntryIdClass;
 import com.baeldung.hibernate.pojo.OrderEntryPK;
+import com.baeldung.hibernate.pojo.Product;
 import com.baeldung.hibernate.pojo.Student;
+import com.baeldung.hibernate.pojo.TennisPlayer;
 import com.baeldung.hibernate.pojo.User;
 import com.baeldung.hibernate.pojo.UserProfile;
 
 public class IdentifiersIntegrationTest {
+
     private Session session;
 
     private Transaction transaction;
@@ -37,12 +43,32 @@ public void tearDown() {
     }
 
     @Test
-    public void whenSaveSimpleIdEntities_thenOk() {
+    public void whenSavingTennisPlayerWithoutAnId_thenSavingEntityOk() {
+        TennisPlayer tennisPlayer = new TennisPlayer("Tom");
+        session.save(tennisPlayer);
+        assertThat(tennisPlayer.getPlayerId()).isEqualTo(0L);
+    }
+
+    @Test
+    public void whenSavingBaseballPlayerWithoutAnId_thenSavingEntityFails() {
+        BaseballPlayer baseballPlayer = new BaseballPlayer("Jerry");
+        assertThatThrownBy(() -> session.save(baseballPlayer)).isInstanceOf(IdentifierGenerationException.class)
+            .hasMessageContaining("ids for this class must be manually assigned before calling save()");
+    }
+    @Test
+    public void whenSavingBaseballPlayerWithAManualId_thenSavingEntityOK() {
+        BaseballPlayer baseballPlayer = new BaseballPlayer("Jerry");
+        baseballPlayer.setPlayerId(42L);
+        session.save(baseballPlayer);
+    }
+
+    @Test
+    public void whenSaveSequenceIdEntities_thenOk() {
         Student student = new Student();
         session.save(student);
         User user = new User();
         session.save(user);
-       
+
         assertThat(student.getStudentId()).isEqualTo(1L);
         assertThat(user.getUserId()).isEqualTo(4L);
 
@@ -103,4 +129,4 @@ public void whenSaveDerivedIdEntity_thenOk() {
         assertThat(profile.getProfileId()).isEqualTo(user.getUserId());
     }
 
-}
+}