Developing web applications applying hibernate framework

Ngày nay, một số lượng lớn các trang web đã được tạo ra cho nhiều mục đích. Cùng với đó là sự phát triển của các framework lập trình web như Express, Laravel, Spring,… Hibernate framework ra đời là hệ quả tất yếu của sự phát triển chung và chứng tỏ giá trị của nó. Trọng lượng nhẹ, hiệu suất nhanh và tạo bảng tự động chỉ là một số ưu điểm của nó khiến Hibernate trở thành lựa chọn được lựa chọn cho dự án. Mời các bạn cùng tham khảo chi tiết nội dung bài viết!

DEVELOPING WEB APPLICATIONS APPLYING HIBERNATE

FRAMEWORK

SVTH: Nguyễn Khắc HIếu, Nguyễn Tuấn Anh, Trần Việt Dung, Lâm Thị Thương Huyền,

Vũ Thành Trung, Lê Thị Lan GVHD: ThS Đỗ Thùy Dương

Tóm tắt - Ngày nay, một số lượng lớn các trang web đã được tạo ra cho nhiều mục đích Cùng với đó là sự phát triển của các framework lập trình web như Express, Laravel, Spring,… Hibernate framework ra đời là hệ quả tất yếu của sự phát triển chung và chứng tỏ giá trị của nó Trọng lượng nhẹ, hiệu suất nhanh và tạo bảng tự động chỉ là một số ưu điểm của nó khiến Hibernate trở thành "lựa chọn được lựa chọn" cho dự án

Abstract - Now days, a large number of websites have been created for plenty purposes Along with that is the development of web programming framework such as Express, Laravel, Spring, and etc Hibernate framework comes an inevitable consequence of general development and proves its worth Lightweight, fast performance, and automatic table creation are only some of its advantages which make Hibernate become “the chosen one” for the project

Keywords – Hibernate, ORM, Object Mapping

I INTRODUCTION

Hibernate also known as Hibernate ORM is a framework for Java programming

language which was developed by Red hat, an American multinational Software company, in

2001 It reduces the complexities from a process of developing a java application to interact with the database It is an open source, lightweight, and ORM (Object Relational Mapping) tool Hibernate applies JPA (Java Persistence API) for the perseverance of data [1]

There are lots of benefits from Hibernate, such as open source and lightweight, fast performance, database independent query, scalability, lazy-loading, and the most important advantage, easy to learn [2] which is the main reason why Hibernate was selected to be

applied in this project

The project Online Banking Application is sensible to use Hibernate framework

because a banking app often has to handle large amount of data and work much with

database Besides, in some cases, there is a huge number of users accessing at the same time,

it requires the web app to provide with a fast speed of processing

II MAIN CONTENT

A What is Hibernate?

Hibernate is a Java framework that makes it easier to create database-interactive Java applications It's an ORM (Object Relational Mapping) tool that's open source and

lightweight For data persistence, Hibernate implements the JPA (Java Persistence API) specifications

Hibernate offers an abstraction layer, which means that the programmer doesn't have to think about the implementations; Hibernate handles them internally, such as establishing a database link, writing queries to perform CRUD operations, and etc

B Why Hibernate?

As regarded above, Hibernate is one of the most popular Java frameworks that bring a lot of advantages for developer:

1 Open source and lightweight: Hibernate Framework is an open source with LGPL license and is lightweight

2 Fast Performance: The performance of Hibernate Framework is fast because the cache is used internally by Hibernate Framework There are two types of cache in Hibernate Framework, the first level cache and the second level cache First level cache is enabled by default

3 Independent Database Query: HQL (Hibernate Query Language) is the object-oriented version of SQL It creates independent database queries So, you don't need to write database specific queries Before Hibernate, if the project had the database changed, we needed to change the SQL query leading to maintenance problem

4 Automated table creation: Hibernate framework provides a means to create database tables automatically Therefore, there is no need to create tables in the database manually

5 Simple complex join command: It is possible to get data from multiple tables easily with Hibernate framework

6 Provides query statistics and database state: Hibernate supports query cache and provides statistics about the query and the state of the database [2]

C How does Hibernate work?

1 Hibernate Architecture

As you can see in the diagram below, the amount of Hibernate you use is determined by your requirements Hibernate offers a lightweight architecture that only deals with ORM at its most basic level Most aspects of persistence, such as transaction, entity/query caching, and link pooling, are entirely abstracted when Hibernate is used in its entirety

The success of Hibernate is due to the simplicity of its core concepts The Hibernate Session is at the heart of any connection between your code and the database If you are familiar with Hibernate, the following picture offers a summary of how it operates and does not include any clarification

The configuration is at the core of every Hibernate program In any Hibernate application, two pieces of configuration are required: one creates the database connections, and the other creates the object-to-table mapping

Let's see the basic introduction to all the components and their roles in hibernate

2 Configure the Database Connection (.cfg.xml)

In order to create a connection to our database, Hibernate needs to know about our tables, classes, and other mechanics This information should be viewed as an XML file (typically called hibernate.cfg.xml) or a simple text file with name/value pairs (usually named hibernate.properties)

The data is in XML format This file is called hibernate.cfg.xml so that it can be loaded automatically by the framework

The following snippet describes such a configuration file Because I am using MySQL

as the database, the connection details for the MySQL database are declared in this hibernate.cfg.xml file:

The preceding properties can also be expressed as name/value pairs

3 The Hibernate Session

The Hibernate Session is a persistence service (or persistence manager) that can be used

to query and perform insert, update, and delete operations on Hibernate-mapped class instances All of these interactions are performed using object oriented semantics in an ORM tool; that is, instead of using tables and columns, you use Java classes and object properties The Session is a lightweight, short-lived entity that acts as a bridge between the application and the database during a conversation The Session wraps the underlying JDBC connection

or J2EE data source, and it serves as a first-level cache for persistent objects bound to it

4 The Session Factory

Hibernate allows you to send it the details it needs to link to each database that an application uses, as well as which classes are mapped to each database The SessionFactory, which is used to retrieve Hibernate Sessions, compiles and caches each

of these database-specific configuration files, as well as the corresponding class mappings The SessionFactory is a large object that should preferably be generated only once (due to its high cost and slowness) and made accessible to application code that requires persistence operations

Using one of the given Hibernate dialects, each SessionFactory is designed to operate with a specific database platform When using database-specific features including native primary key generation schemes or Session locking, the Hibernate dialect you use is crucial

At the time of this writing Hibernate (version 3.1) supports 22 database dialects Each of the dialect implementations are in the package org.hibernate.dialect

5 The Hibernate Object Mappings

Hibernate uses an XML configuration file to specify how each object state is retrieved and stored in the database Hibernate mappings are loaded and cached in the SessionFactory

at startup Each mapping specifies a variety of parameters related to the persistence lifecycle

of instances of the mapped class such as:

• Primary key mapping and generation scheme

• Object-field-to-table-column mappings

• Associations/Collections

• Caching settings

• Custom SQL, store procedure calls, filters, parameterized queries, and more

6 Persistence Lifecycle of Hibernate

There are three possible states for a Hibernate mapped object Understanding these states and the actions that cause state transitions will become very important when dealing with the more complex Hibernate problems

The object is not associated with a database table in the transient state That is, the object's state has not been saved to a table, and it has no database identity (no primary key has been assigned) Objects in the transient state are non-transactional, which means they don't engage in any Hibernate Session-bound transactions After a successful invocation of the save

or saveOrUpdate methods an object ceases to be transient and becomes persistent The Session delete method (or a delete query) produces the inverse effect making a persistent object transient

Persistent objects are those that have a database ID (They are referred to as being in the

"latest" state if they have been allocated a primary key but have not yet been saved to the database.) Persistent objects are transactional, which means that they take part in the Session's transactions (at the end of the transaction the object state will be synchronized with the database)

A disconnected object is a persistent object that is no longer in the Session cache (and

hence no longer connected with the Session) When a transaction is completed, the Session is

terminated, cleared, or the object is directly evicted from the Session cache, this occurs

Objects in the detached state can essentially become inter tier transfer objects, and in some

applications, architectures can replace the need for DTOs, thanks to Hibernate's transparency

when it comes to providing persistent services to an object (Data Transfer Objects)

D Results of work

By applying Hibernate to the project, we have completed the project with all the

necessary features Our project is about online banking via a website, built on top of

Java-jsp-servlet We have divided our project into two main roles that are Admin and Customer

1 Admin

In Admin roles, there are main seven features for this role Admin is the person

responsible for managing the bank's data and managing the main tasks of the customer

segment such as opening accounts, locking accounts, or basic online banking operations such

as withdrawing and transferring money online, check transaction information as well as

transaction history Admin can also view detailed information for a particular account

Admin can create a new account with necessary information of user After click submit,

username and password as well as transaction password have been displayed on scree as

below:

For closing and viewing a particular account, Admin need to enter account number for executing

The same for viewing a particular account information:

Apart from the above, deposit and withdraw function require to input account number and amount to be deposited or withdrawn:

Another feature is Fund Transfer, this function can be handled by entering source account number, target account number and amount to be transferred:

Finally, admin can also check the history information about transactions of particular account by inputting their account number:

2 Customer

On the other hand, Customer features is more limited than Admin with four main functions

Firstly, customer can view their account information by click on View Account tab Furthermore, customer also can transfer their money to another account within inputting correct data

After transferring successfully, user can check the transaction history for personal reasons Another important point is that customer can change their security information, which are user name, password and transaction password

For detail demonstration, we have to represented it in our screencast video

III CONCLUSION

In general, Hibernate framework has shown that it is a useful framework for developing website application with many powerful features Hibernate is such one of the most suitable for student project In this paper, we delivered a brief discussion of the Hibenate and a basic demo application about Bank Management system

REFERENCE

[1] Website: Javapoint (2011-2018) Hibernate https://www.javatpoint.com/hibernate-tutorial

[2] Website: Chandrashekhar (July 2015) Top 10 Advantages of Hibernate https://www.onlinetutorialspoint.com/hibernate/top-10-advantages-of-hibernate.html