BAEL-6556 - TupleTransformer and ResultListTransformer in Hibernate (#18791)

* experiments

* bael-6556 - complete

* bael-6556 fix line break at EOF

Author: ulisseslima

persistence-modules/hibernate6/pom.xml

@@ -82,4 +82,4 @@
         <maven.compiler.target>17</maven.compiler.target>
     </properties>
 
-</project>
+</project>

persistence-modules/hibernate6/src/main/java/com/baeldung/transformers/TransformersApplication.java

@@ -0,0 +1,14 @@
+package com.baeldung.transformers;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.PropertySource;
+
+@PropertySource("classpath:application-transformers.yaml")
+@SpringBootApplication(scanBasePackageClasses = TransformersApplication.class)
+public class TransformersApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(TransformersApplication.class, args);
+    }
+}

persistence-modules/hibernate6/src/main/java/com/baeldung/transformers/dto/DepartmentStudentsDto.java

@@ -0,0 +1,6 @@
+package com.baeldung.transformers.dto;
+
+import java.util.List;
+
+public record DepartmentStudentsDto(String department, List<String> students) {
+}

persistence-modules/hibernate6/src/main/java/com/baeldung/transformers/dto/StudentDto.java

@@ -0,0 +1,4 @@
+package com.baeldung.transformers.dto;
+
+public record StudentDto(Long id, String name) {
+}

persistence-modules/hibernate6/src/main/java/com/baeldung/transformers/entity/Course.java

@@ -0,0 +1,52 @@
+package com.baeldung.transformers.entity;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name = "courses")
+public class Course {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+    private String name;
+
+    @ManyToOne
+    private Department department;
+
+    protected Course() {
+    }
+
+    public Course(String name, Department department) {
+        this.name = name;
+        this.department = department;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Department getDepartment() {
+        return department;
+    }
+
+    public void setDepartment(Department department) {
+        this.department = department;
+    }
+}

persistence-modules/hibernate6/src/main/java/com/baeldung/transformers/entity/Department.java

@@ -0,0 +1,42 @@
+package com.baeldung.transformers.entity;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name = "departments")
+public class Department {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+    private String name;
+
+    @OneToMany(mappedBy = "department")
+    private List<Student> students = new ArrayList<>();
+
+    protected Department() {
+    }
+
+    public Department(String name) {
+        this.name = name;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public List<Student> getStudents() {
+        return students;
+    }
+}

persistence-modules/hibernate6/src/main/java/com/baeldung/transformers/entity/Enrollment.java

@@ -0,0 +1,54 @@
+package com.baeldung.transformers.entity;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name = "enrollments")
+public class Enrollment {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @ManyToOne
+    private Student student;
+
+    @ManyToOne
+    private Course course;
+
+    protected Enrollment() {
+    }
+
+    public Enrollment(Student student, Course course) {
+        this.student = student;
+        this.course = course;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Student getStudent() {
+        return student;
+    }
+
+    public void setStudent(Student student) {
+        this.student = student;
+    }
+
+    public Course getCourse() {
+        return course;
+    }
+
+    public void setCourse(Course course) {
+        this.course = course;
+    }
+}

persistence-modules/hibernate6/src/main/java/com/baeldung/transformers/entity/PersonEntity.java

@@ -0,0 +1,39 @@
+package com.baeldung.transformers.entity;
+
+
+import org.hibernate.annotations.Cache;
+import org.hibernate.annotations.CacheConcurrencyStrategy;
+
+import jakarta.persistence.Cacheable;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.SequenceGenerator;
+
+@Entity
+@Cacheable
+@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+public class PersonEntity {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "PERSON_SEQ")
+    @SequenceGenerator(name = "PERSON_SEQ", sequenceName = "PERSON_SEQ", allocationSize = 100)
+    private Long id;
+
+    private String name;
+    private Long mobile;
+    private String designation;
+
+    public String getName() {
+        return name;
+    }
+
+    public Long getMobile() {
+        return mobile;
+    }
+
+    public String getDesignation() {
+        return designation;
+    }
+}

persistence-modules/hibernate6/src/main/java/com/baeldung/transformers/entity/Student.java

@@ -0,0 +1,52 @@
+package com.baeldung.transformers.entity;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+@Entity
+@Table(name = "students")
+public class Student {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+    private String name;
+
+    @ManyToOne
+    private Department department;
+
+    protected Student() {
+    }
+
+    public Student(String name, Department department) {
+        this.name = name;
+        this.department = department;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public Department getDepartment() {
+        return department;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public void setDepartment(Department department) {
+        this.department = department;
+    }
+}

persistence-modules/hibernate6/src/main/resources/application-transformers.yaml

@@ -0,0 +1,18 @@
+spring:
+  config:
+    name: application-transformers
+  sql:
+    init:
+      mode: never
+  datasource:
+    url: jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1
+    driverClassName: org.h2.Driver
+    username: sa
+    password:
+  jpa:
+    hibernate:
+      ddl-auto: create-drop
+    show-sql: true
+    properties:
+      hibernate:
+        format_sql: true