package edu.hibernate.example;<\/em><\/strong><\/p>\n\n\n\nimport java.util.List;\nimport java.util.Iterator;\n\nimport org.hibernate.HibernateException;\nimport org.hibernate.Session;\nimport org.hibernate.Transaction;\nimport org.hibernate.SessionFactory;\nimport org.hibernate.cfg.Configuration;\n\npublic class CustomerService {\nprivate static SessionFactory factory;\n\npublic CustomerService() {\ntry {\nfactory = new Configuration().configure().buildSessionFactory();\n} catch (Throwable ex) {\nSystem.err.println(\"Failed to create sessionFactory object.\" + ex);\nthrow new ExceptionInInitializerError(ex);\n}\n\n}\n\npublic Integer addCustomer(String firstname, String lastname, String email) {\nSession session = factory.openSession();\nTransaction transaction = null;\nInteger customerID = null;\n\ntry {\ntransaction = session.beginTransaction();\nCustomer customer = new Customer(firstname, lastname, email);\ncustomerID = (Integer) session.save(customer);\ntransaction.commit();\n} catch (HibernateException e) {\nif (transaction != null)\ntransaction.rollback();\ne.printStackTrace();\n} finally {\nsession.close();\n}\nreturn customerID;\n}\n\npublic List listCustomers() {\nSession session = factory.openSession();\nTransaction transaction = null;\nList customers = null;\ntry {\ntransaction = session.beginTransaction();\ncustomers = session.createQuery(\"FROM Customer\").list();\ntransaction.commit();\nreturn customers;\n} catch (HibernateException e) {\nif (transaction != null)\ntransaction.rollback();\ne.printStackTrace();\n} finally {\nsession.close();\n}\nreturn customers;\n}\n\npublic void updateCustomer(Integer CustomerID, String email) {\nSession session = factory.openSession();\nTransaction transaction = null;\n\ntry {\ntransaction = session.beginTransaction();\nCustomer customer = (Customer) session.get(Customer.class, CustomerID);\ncustomer.setEmail(email);\nsession.update(customer);\ntransaction.commit();\n} catch (HibernateException e) {\nif (transaction != null)\ntransaction.rollback();\ne.printStackTrace();\n} finally {\nsession.close();\n}\n}\n\npublic void deleteCustomer(Integer CustomerID) {\nSession session = factory.openSession();\nTransaction transaction = null;\n\ntry {\ntransaction = session.beginTransaction();\nCustomer customer = (Customer) session.get(Customer.class, CustomerID);\nsession.delete(customer);\ntransaction.commit();\n} catch (HibernateException e) {\nif (transaction != null)\ntransaction.rollback();\ne.printStackTrace();\n} finally {\nsession.close();\n}\n}\n}\n<\/pre>\n\n\n\nFinally, we got this project hierarchy:<\/em><\/strong><\/p>\n\n\n\n![\"\"](\"https:\/\/lh3.googleusercontent.com\/2Z_rrI33s-y7jbjozat0Arl_3pGvoQh8AJ4pYVw3ZkFGJmdMp4iNybWqNdXfV3J47BiZBDWTJATUrqnOBc3VH9pvBG2aNrjR0JcMLYZ2ZwL7VrsXFk6ttQpnJTmOqykFbZzAqShf\" "\\"\\"")
<\/p>\n\n\n\n
Here is our main method of the application:<\/em><\/strong><\/p>\n\n\n\npackage edu.hibernate.example;\n\nimport java.util.Iterator;\nimport java.util.List;\n\npublic class HibernateExample {\n\npublic static void main(String[] args) {\n\n CustomerService customerService = new CustomerService();\n Integer customerID1 = customerService.addCustomer(\"Bob\", \"Lie\", \"bob@gmail.com\");\n System.out.println(\"List of Customers after creation of the new record:\");\n printListCustomers(customerService.listCustomers());\n \n customerService.updateCustomer(customerID1, \"bobLie@gmail.com\");\n System.out.println(\"List of Customers after updating the record:\");\n printListCustomers(customerService.listCustomers());\n \n customerService.deleteCustomer(customerID1);\n System.out.println(\"List of Customers after deleting the record:\"); \n printListCustomers(customerService.listCustomers());\n\n}\n\nprivate static void printListCustomers(List customers) {\nif(!customers.iterator().hasNext()) {\nSystem.out.println(\"The list is empty!\");\n}\nfor (Iterator iterator = customers.iterator(); iterator.hasNext();) {\nCustomer customer = (Customer) iterator.next();\nSystem.out.print(\"First Name: \" + customer.getFirstName());\nSystem.out.print(\" Last Name: \" + customer.getLastName());\nSystem.out.println(\" Email: \" + customer.getEmail());\n}\n}\n}\n<\/pre>\n\n\n\nThe output of our application is:<\/em><\/strong><\/p>\n\n\n[box type=”info” align=”” class=”” width=””]List of Customers after creation of the new record:
First Name: Bob Last Name: Lie Email: bob@gmail.com
List of Customers after updating the record:
First Name: Bob Last Name: Lie Email: bobLie@gmail.com
List of Customers after deleting the record:
The list is empty!
[\/box]<\/p>\n\n\n
So, we successfully created the Java project and implemented base CRUD operations (create, read, update, delete) with the help of the Hibernate framework and with the use of MySQL database.<\/p>\n\n\n\n
We have used the XML mapping file for the transformation. But there is another way to do this. The Hibernate annotations are a new way to do this without the use of the XML file. You can use mixed-method: annotations and XML mapping together.<\/p>\n\n\n\n
In this case, our Java POJO class will look like this:<\/em><\/strong><\/p>\n\n\n\npackage<\/strong> edu.hibernate.example;\n\nimport<\/strong> javax.persistence.Column;\nimport<\/strong> javax.persistence.Entity;\nimport<\/strong> javax.persistence.GeneratedValue;\nimport<\/strong> javax.persistence.Id;\nimport<\/strong> javax.persistence.Table;\n\n@Entity\n@Table(name = \"CUSTOMER\")\npublic<\/strong> class<\/strong> Customer {\n@Id @GeneratedValue\n@Column(name = \"id\")\nprivate<\/strong> int<\/strong> id;\n@Column(name = \"first_name\")\nprivate<\/strong> String firstName;\n@Column(name = \"last_name\")\nprivate<\/strong> String lastName;\n@Column(name = \"email\")\nprivate<\/strong> String email;\npublic<\/strong> Customer (String firstName, String lastName, String email) {\nsuper<\/strong>();\nthis<\/strong>.firstName = firstName;\nthis<\/strong>.lastName = lastName;\nthis<\/strong>.email = email;\n}\npublic<\/strong> Customer() {\n}\npublic<\/strong> int<\/strong> getId() {\nreturn<\/strong> id;\n}\npublic<\/strong> void<\/strong> setId(int<\/strong> id) {\nthis<\/strong>.id = id;\n}\npublic<\/strong> String getFirstName() {\nreturn<\/strong> firstName;\n}\npublic<\/strong> void<\/strong> setFirstName(String firstName) {\nthis<\/strong>.firstName = firstName;\n}\npublic<\/strong> String getLastName() {\nreturn<\/strong> lastName;\n}\npublic<\/strong> void<\/strong> setLastName(String lastName) {\nthis<\/strong>.lastName = lastName;\n}\npublic<\/strong> String getEmail() {\nreturn<\/strong> email;\n}\npublic<\/strong> void<\/strong> setEmail(String email) {\nthis<\/strong>.email = email;\n}\n}\n<\/pre>\n\n\n\nThere are more annotations. There is the way to define one-to-one, one-to-many and many-to-many relationships between classes with annotations too.<\/p>\n\n\n\n
We will also need to do small changes inCustomerService class for SessionFactory builder:<\/p>\n\n\n\n
public<\/strong> class<\/strong> CustomerService {\nprivate<\/strong> static<\/strong> SessionFactory factory<\/em>;\n\npublic<\/strong> CustomerService() {\ntry<\/strong> {\nfactory<\/em> = new<\/strong> AnnotationConfiguration().\n configure().\n \/\/addPackage(\"edu.hibernate.example\") \/\/add package if used.\n addAnnotatedClass(Customer.class<\/strong>).\n buildSessionFactory();\n} catch<\/strong> (Throwable ex) {\nSystem.err<\/em><\/strong>.println(\"Failed to create sessionFactory object.\" + ex);\nthrow<\/strong> new<\/strong> ExceptionInInitializerError(ex);\n}\n\n}\n...\n}\n<\/pre>\n\n\n\nOther code in our code wouldn’t be changed. All the annotations are from javax.persistence package. XML<\/strong><\/em> mappings have greater flexibility, but for portability to other EJB 3 compliant ORM applications, you must use annotations.<\/p>\n","protected":false},"excerpt":{"rendered":"Let’s create our first Java application with Hibernate technology. One of the simplest ways is to create a basic Maven project and to add Hibernate dependency to pom.xml. The version of the Hibernate framework can vary: <dependency> <groupId>org.hibernate<\/groupId> <artifactId>hibernate-agroal<\/artifactId> <version>5.4.17.Final<\/version> <type>pom<\/type> <\/dependency> We are going to use the MySQL database. So, you need to make […]<\/p>\n","protected":false},"author":1,"featured_media":3816,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[42],"tags":[1007,1008,1009],"class_list":["post-3791","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java-tutorials","tag-hibernate-program","tag-java-application","tag-java-pojo"],"_links":{"self":[{"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/posts\/3791","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/comments?post=3791"}],"version-history":[{"count":0,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/posts\/3791\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/media\/3816"}],"wp:attachment":[{"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/media?parent=3791"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/categories?post=3791"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.h2kinfosys.com\/blog\/wp-json\/wp\/v2\/tags?post=3791"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
![\"\"](\"https:\/\/lh4.googleusercontent.com\/CO-8-MurENILttNsRpnCZ8vKQX7PkE-kX5Oitff4wB3AlnP-o8NjE8QmHL9PxxcF21iPkEU275HEZqom3K2a1KxBDcyps4ouwuCxBukI4mAwM0cUcwY9EfR8ZV8dTRULAi6wGwDr\" "\\"\\"")
<\/p>\n\n\n\n