Hibernate is an ORM tool that provides object/relational mapping and persistence services. It allows developers to work with Java objects instead of SQL and relational data. Hibernate supports different levels of object/relational mapping from pure relational to full object mapping. Some key benefits of Hibernate include increased productivity, maintainability, performance, and vendor independence.
These question are the basic questions for Interview based on Java language. These questions are able to crack the interview based on java language
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In this Java Spring Training session, you will learn Spring AOP – Aspect Oriented Programming Topics covered in this session are:
For more information, visit this link:
• Auto-wiring
• Annotations based configuration
• Java based configuration
https://www.mindsmapped.com/courses/software-development/spring-fundamentals-learn-spring-framework-and-spring-boot/
These question are the basic questions for Interview based on Java language. These questions are able to crack the interview based on java language
Learn more at blog : --
https://solutionbyexpert.blogspot.com/2020/08/become-expert-secret-of-success-ii.html
#coding
#coding development skill program
#java
In this Java Spring Training session, you will learn Spring AOP – Aspect Oriented Programming Topics covered in this session are:
For more information, visit this link:
• Auto-wiring
• Annotations based configuration
• Java based configuration
https://www.mindsmapped.com/courses/software-development/spring-fundamentals-learn-spring-framework-and-spring-boot/
Crack your Java interview by knowing all the questions that your interviewer may ask. Brush up your knowledge with this superb set of Java interview questions & answers prepared by BestOnlineTrainers
9 crucial Java Design Principles you cannot missMark Papis
Encapsulation, Polymorphism, Agreggation / Composition, Overloading, Inheritance vs Composition, DRY, Dependency Injection, Delagation, Law of demeter, Principle of leas knowledge,
In this core java training session, you will learn Java IO – Files, Streams and
Object Serialization. Topics covered in this session are:
• Java IO
• Files
• Streams
• Byte-based
• Character-based
• Object Serialization
For more information about this course visit on this link: https://www.mindsmapped.com/courses/software-development/learn-java-fundamentals-hands-on-training-on-core-java-concepts/
In this Java JSP Training session, you will learn JSP. Topics covered in this session are:
• JSP (Java Server Pages Technology)
• JSP vs Servlet
• MVC Architecture
• Scriplet
For more information, visit this link:
https://www.mindsmapped.com/courses/software-development/jsp-and-servlets-designing-web-applications-with-java/
In this Java Hibernate Training session, you will learn Hibernate part -2. Topics covered in this session are:
• Generator Class in Hibernate
• SQL Dialects
• Collection Mapping
• One-to-one Mapping
• Cascade Types
• Many to one / One to many
• Hibernate Lazy Loading
• Transaction Management
• HQL – Hibernate Query Language
• HCQL – Hibernate Criteria Query Language
• Hibernate Caching
For more information, visit this link:
https://www.mindsmapped.com/courses/software-development/learn-hibernate-fundamentals-from-scratch/
A hibernate tutorial for beginners. It describe the hibernate concepts in a lucid manner and and test project(User application with database) to get hands on over the same.
YouTube Link: https://youtu.be/2sCAw1EbfEQ
Hibernate Certification: https://www.edureka.co/persistence-with-hibernate-self-paced
This Edureka PPT on "Hibernate Interview Questions" video will help you prepare for the role of a Hibernate Developer.
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This PPT, will be very helpful for Engineering candidates specially frehsers who have opted .net . For more details log in to www.rekruitin.com
By ReKruiTIn.com
Crack your Java interview by knowing all the questions that your interviewer may ask. Brush up your knowledge with this superb set of Java interview questions & answers prepared by BestOnlineTrainers
9 crucial Java Design Principles you cannot missMark Papis
Encapsulation, Polymorphism, Agreggation / Composition, Overloading, Inheritance vs Composition, DRY, Dependency Injection, Delagation, Law of demeter, Principle of leas knowledge,
In this core java training session, you will learn Java IO – Files, Streams and
Object Serialization. Topics covered in this session are:
• Java IO
• Files
• Streams
• Byte-based
• Character-based
• Object Serialization
For more information about this course visit on this link: https://www.mindsmapped.com/courses/software-development/learn-java-fundamentals-hands-on-training-on-core-java-concepts/
In this Java JSP Training session, you will learn JSP. Topics covered in this session are:
• JSP (Java Server Pages Technology)
• JSP vs Servlet
• MVC Architecture
• Scriplet
For more information, visit this link:
https://www.mindsmapped.com/courses/software-development/jsp-and-servlets-designing-web-applications-with-java/
In this Java Hibernate Training session, you will learn Hibernate part -2. Topics covered in this session are:
• Generator Class in Hibernate
• SQL Dialects
• Collection Mapping
• One-to-one Mapping
• Cascade Types
• Many to one / One to many
• Hibernate Lazy Loading
• Transaction Management
• HQL – Hibernate Query Language
• HCQL – Hibernate Criteria Query Language
• Hibernate Caching
For more information, visit this link:
https://www.mindsmapped.com/courses/software-development/learn-hibernate-fundamentals-from-scratch/
A hibernate tutorial for beginners. It describe the hibernate concepts in a lucid manner and and test project(User application with database) to get hands on over the same.
YouTube Link: https://youtu.be/2sCAw1EbfEQ
Hibernate Certification: https://www.edureka.co/persistence-with-hibernate-self-paced
This Edureka PPT on "Hibernate Interview Questions" video will help you prepare for the role of a Hibernate Developer.
Follow us to never miss an update in the future.
YouTube: https://www.youtube.com/user/edurekaIN
Instagram: https://www.instagram.com/edureka_learning/
Facebook: https://www.facebook.com/edurekaIN/
Twitter: https://twitter.com/edurekain
LinkedIn: https://www.linkedin.com/company/edureka
Castbox: https://castbox.fm/networks/505?country=in
This PPT, will be very helpful for Engineering candidates specially frehsers who have opted .net . For more details log in to www.rekruitin.com
By ReKruiTIn.com
Some of the common interview questions asked during a Java Interview. These may apply to Java Interviews. Be prepared with answers for the interview questions below when you prepare for an interview. Also have an example to explain how you worked on various interview questions asked below. Java Developers are expected to have references and be able to explain from their past experiences. All the Best for a successful career as a Java Developer!
Some of the common interview questions asked during a Java Interview. These may apply to Java Interviews. Be prepared with answers for the interview questions below when you prepare for an interview. Also have an example to explain how you worked on various interview questions asked below. Java Developers are expected to have references and be able to explain from their past experiences. All the Best for a successful career as a Java Developer!
Hibernate Interview Questions and AnswersAnuragMourya8
Hibernate is an open-source object-relational mapping (ORM) framework for Java. It provides a mapping between Java objects and relational database tables, allowing developers to work with databases using Java objects directly.
Finally Practice here most popular Hibernate Interview Questions and Answers.
Top 20 Asp.net interview Question and answersw3asp dotnet
It is about .net interview question and answers.W3asp.net is a site which provide you the information regarding asp.net like c# ,asp.net, SQLSERVER,XML,Winforms. w3asp.net also organize quizzes and job.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
To Graph or Not to Graph Knowledge Graph Architectures and LLMs
Hibernate interview questions
1. Hibernate Interview Questions
1. What is Hibernate?
Hibernate is a powerful, high performance object/relational persistence and query service.
This lets the users to develop persistent classes following object-oriented principles such
as association, inheritance, polymorphism, composition, and collections.
2. What is ORM?
ORM stands for Object/Relational mapping. It is the programmed and translucent
perseverance of objects in a Java application in to the tables of a relational database using
the metadata that describes the mapping between the objects and the database. It works
by transforming the data from one representation to another.
3. What does an ORM solution comprises of?
• It should have an API for performing basic CRUD (Create, Read, Update, Delete)
operations on objects of persistent classes
• Should have a language or an API for specifying queries that refer to the classes
and the properties of classes
• An ability for specifying mapping metadata
• It should have a technique for ORM implementation to interact with transactional
objects to perform dirty checking, lazy association fetching, and other optimization
functions
4. What are the different levels of ORM quality?
There are four levels defined for ORM quality.
i. Pure relational
ii. Light object mapping
iii. Medium object mapping
iv. Full object mapping
5. What is a pure relational ORM?
The entire application, including the user interface, is designed around the relational
model and SQL-based relational operations.
6. What is a meant by light object mapping?
The entities are represented as classes that are mapped manually to the relational tables.
The code is hidden from the business logic using specific design patterns. This approach
is successful for applications with a less number of entities, or applications with common,
metadata-driven data models. This approach is most known to all.
7. What is a meant by medium object mapping?
The application is designed around an object model. The SQL code is generated at build
time. And the associations between objects are supported by the persistence mechanism,
and queries are specified using an object-oriented expression language. This is best suited
2. for medium-sized applications with some complex transactions. Used when the mapping
exceeds 25 different database products at a time.
8. What is meant by full object mapping?
Full object mapping supports sophisticated object modeling: composition, inheritance,
polymorphism and persistence. The persistence layer implements transparent persistence;
persistent classes do not inherit any special base class or have to implement a special
interface. Efficient fetching strategies and caching strategies are implemented
transparently to the application.
9. What are the benefits of ORM and Hibernate?
There are many benefits from these. Out of which the following are the most important
one.
i. Productivity – Hibernate reduces the burden of developer by providing much of
the functionality and let the developer to concentrate on business logic.
ii. Maintainability – As hibernate provides most of the functionality, the LOC for the
application will be reduced and it is easy to maintain. By automated object/relational
persistence it even reduces the LOC.
iii. Performance – Hand-coded persistence provided greater performance than
automated one. But this is not true all the times. But in hibernate, it provides more
optimization that works all the time there by increasing the performance. If it is
automated persistence then it still increases the performance.
iv. Vendor independence – Irrespective of the different types of databases that are
there, hibernate provides a much easier way to develop a cross platform application.
10. How does hibernate code looks like?
Session session = getSessionFactory().openSession();
Transaction tx = session.beginTransaction();
MyPersistanceClass mpc = new MyPersistanceClass ("Sample App");
session.save(mpc);
tx.commit();
session.close();
The Session and Transaction are the interfaces provided by hibernate. There are many
other interfaces besides this.
11. What is a hibernate xml mapping document and how does it look like?
In order to make most of the things work in hibernate, usually the information is provided
in an xml document. This document is called as xml mapping document. The document
defines, among other things, how properties of the user defined persistence classes’ map
to the columns of the relative tables in database.
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class name="sample.MyPersistanceClass" table="MyPersitaceTable">
<id name="id" column="MyPerId">
3. <generator class="increment"/>
</id>
<property name="text" column="Persistance_message"/>
<many-to-one name="nxtPer" cascade="all" column="NxtPerId"/>
</class>
</hibernate-mapping>
Everything should be included under <hibernate-mapping> tag. This is the main tag for
an xml mapping document.
12. Show Hibernate overview?
`
13. What the Core interfaces are of hibernate framework?
There are many benefits from these. Out of which the following are the most important
one.
i. Session Interface – This is the primary interface used by hibernate applications.
The instances of this interface are lightweight and are inexpensive to create and destroy.
Hibernate sessions are not thread safe.
4. ii. SessionFactory Interface – This is a factory that delivers the session objects to
hibernate application. Generally there will be a single SessionFactory for the whole
application and it will be shared among all the application threads.
iii. Configuration Interface – This interface is used to configure and bootstrap
hibernate. The instance of this interface is used by the application in order to specify the
location of hibernate specific mapping documents.
iv. Transaction Interface – This is an optional interface but the above three interfaces
are mandatory in each and every application. This interface abstracts the code from any
kind of transaction implementations such as JDBC transaction, JTA transaction.
v. Query and Criteria Interface – This interface allows the user to perform queries
and also control the flow of the query execution.
14. What are Callback interfaces?
These interfaces are used in the application to receive a notification when some object
events occur. Like when an object is loaded, saved or deleted. There is no need to
implement callbacks in hibernate applications, but they’re useful for implementing
certain kinds of generic functionality.
15. What are Extension interfaces?
When the built-in functionalities provided by hibernate is not sufficient enough, it
provides a way so that user can include other interfaces and implement those interfaces
for user desire functionality. These interfaces are called as Extension interfaces.
16. What are the Extension interfaces that are there in hibernate?
There are many extension interfaces provided by hibernate.
ProxyFactory interface - used to create proxies
ConnectionProvider interface – used for JDBC connection management
TransactionFactory interface – Used for transaction management
Transaction interface – Used for transaction management
TransactionManagementLookup interface – Used in transaction management.
Cahce interface – provides caching techniques and strategies
CacheProvider interface – same as Cache interface
ClassPersister interface – provides ORM strategies
IdentifierGenerator interface – used for primary key generation
Dialect abstract class – provides SQL support
17. What are different environments to configure hibernate?
There are mainly two types of environments in which the configuration of hibernate
application differs.
i. Managed environment – In this kind of environment everything from database
connections, transaction boundaries, security levels and all are defined. An example of
this kind of environment is environment provided by application servers such as JBoss,
Weblogic and WebSphere.
5. ii. Non-managed environment – This kind of environment provides a basic
configuration template. Tomcat is one of the best examples that provide this kind of
environment.
18. What is the file extension you use for hibernate mapping file?
The name of the file should be like this : filename.hbm.xml
The filename varies here. The extension of these files should be “.hbm.xml”.
This is just a convention and it’s not mandatory. But this is the best practice to follow this
extension.
19. What do you create a SessionFactory?
Configuration cfg = new Configuration();
cfg.addResource("myinstance/MyConfig.hbm.xml");
cfg.setProperties( System.getProperties() );
SessionFactory sessions = cfg.buildSessionFactory();
First, we need to create an instance of Configuration and use that instance to refer to the
location of the configuration file. After configuring this instance is used to create the
SessionFactory by calling the method buildSessionFactory().
20. What is meant by Method chaining?
Method chaining is a programming technique that is supported by many hibernate
interfaces. This is less readable when compared to actual java code. And it is not
mandatory to use this format. Look how a SessionFactory is created when we use method
chaining.
SessionFactory sessions = new Configuration()
.addResource("myinstance/MyConfig.hbm.xml")
.setProperties( System.getProperties() )
.buildSessionFactory();
21. What does hibernate.properties file consist of?
This is a property file that should be placed in application class path. So when the
Configuration object is created, hibernate is first initialized. At this moment the
application will automatically detect and read this hibernate.properties file.
hibernate.connection.datasource = java:/comp/env/jdbc/AuctionDB
hibernate.transaction.factory_class =
net.sf.hibernate.transaction.JTATransactionFactory
hibernate.transaction.manager_lookup_class =
net.sf.hibernate.transaction.JBossTransactionManagerLookup
hibernate.dialect = net.sf.hibernate.dialect.PostgreSQLDialect
22. What should SessionFactory be placed so that it can be easily accessed?
As far as it is compared to J2EE environment, if the SessionFactory is placed in JNDI
then it can be easily accessed and shared between different threads and various
components that are hibernate aware. You can set the SessionFactory to a JNDI by
configuring a property hibernate.session_factory_name in the hibernate.properties file.
6. 23. What are POJOs?
POJO stands for plain old java objects. These are just basic JavaBeans that have defined
setter and getter methods for all the properties that are there in that bean. Besides they
can also have some business logic related to that property. Hibernate applications works
efficiently with POJOs rather then simple java classes.
24. What is object/relational mapping metadata?
ORM tools require a metadata format for the application to specify the mapping between
classes and tables, properties and columns, associations and foreign keys, Java types and
SQL types. This information is called the object/relational mapping metadata. It defines
the transformation between the different data type systems and relationship
representations.
25. What is HQL?
HQL stands for Hibernate Query Language. Hibernate allows the user to express queries
in its own portable SQL extension and this is called as HQL. It also allows the user to
express in native SQL.
26. What are the different types of property and class mappings?
• Typical and most common property mapping
<property name="description" column="DESCRIPTION" type="string"/>
Or
<property name="description" type="string">
<column name="DESCRIPTION"/>
</property>
• Derived properties
<property name="averageBidAmount" formula="( select AVG(b.AMOUNT) from BID b
where b.ITEM_ID = ITEM_ID )" type="big_decimal"/>
• Typical and most common property mapping
<property name="description" column="DESCRIPTION" type="string"/>
• Controlling inserts and updates
<property name="name" column="NAME" type="string"
insert="false" update="false"/>
27. What is Attribute Oriented Programming?
XDoclet has brought the concept of attribute-oriented programming to Java. Until JDK
1.5, the Java language had no support for annotations; now XDoclet uses the Javadoc tag
format (@attribute) to specify class-, field-, or method-level metadata attributes. These
attributes are used to generate hibernate mapping file automatically when the application
is built. This kind of programming that works on attributes is called as Attribute Oriented
Programming.
7. 28. What are the different methods of identifying an object?
There are three methods by which an object can be identified.
i. Object identity –Objects are identical if they reside in the same memory location
in the JVM. This can be checked by using the = = operator.
ii. Object equality – Objects are equal if they have the same value, as defined by the
equals( ) method. Classes that don’t explicitly override this method inherit the
implementation defined by java.lang.Object, which compares object identity.
iii. Database identity – Objects stored in a relational database are identical if they
represent the same row or, equivalently, share the same table and primary key value.
29. What are the different approaches to represent an inheritance hierarchy?
i. Table per concrete class.
ii. Table per class hierarchy.
iii. Table per subclass.
30. What are managed associations and hibernate associations?
Associations that are related to container management persistence are called managed
associations. These are bi-directional associations. Coming to hibernate associations,
these are unidirectional.