Hibernate Tutorial

• Introduction to Hibernate Framework
• Hibernate Architecture
• Hibernate Lifecycle
• Difference between JDBC and Hibernate in Java
• JPA vs Hibernate
• Hibernate - Difference Between ORM and JDBC
• Hibernate Example using XML in Eclipse
• Hibernate - Create Hibernate Configuration File with the Help of Plugin

Core Hibernate

• Hibernate - Cache Eviction with Example
• Hibernate - Cache Expiration
• Hibernate - Enable and Implement First and Second Level Cache
• Hibernate - Pagination
• Hibernate - Different Cascade Types
• Hibernate - Caching
• Hibernate - Eager/Lazy Loading
• Hibernate - get() and load() Method
• Hibernate Validator with Example
• Hibernate - Batch Processing
• Hibernate - Interceptors
• Hibernate - Criteria Queries
• Hibernate - Create POJO Classes
• Hibernate - Web Application
• Hibernate - Generator Classes
• Hibernate Example without IDE

Hibernate Mapping

• Hibernate - One-to-One Mapping
• Hibernate - One-to-Many Mapping
• Hibernate - Many-to-One Mapping
• Hibernate - Many-to-Many Mapping
• Hibernate - Component Mapping
• Hibernate - Mapping List
• Hibernate - Collection Mapping
• Hibernate - Bag Mapping
• Hibernate - Difference Between List and Bag Mapping
• Hibernate - SortedSet Mapping
• Hibernate - SortedMap Mapping
• Hibernate - Bidirectional Association
• Hibernate - Lazy Collection

Hibernate Annotations

• Hibernate - Annotations
• Hibernate - @Embeddable and @Embedded Annotation

Hibernate with Spring Framework

• Spring Hibernate Configuration and Create a Table in Database
• Spring ORM Example using Hibernate
• Spring Boot - Validation using Hibernate Validator
• How to Create a Project using Spring MVC and Hibernate 5?
• Spring Boot - Integrating Hibernate and JPA

Hibernate with Database

• Hibernate - Save Image and Other Types of Values to Database
• Hibernate Native SQL Query with Example
• CRUD Operations using Hibernate
• Automatic Table Creation Using Hibernate
• Hibernate - Native SQL
• Hibernate - SQL Dialects
• Hibernate - Query Language
• Hibernate Example using JPA and MySQL

Hibernate Log4j

• Hibernate - Logging by Log4j using xml File
• Hibernate - Logging By Log4j Using Properties File

Inheritance Mapping

• Hibernate - Inheritance Mapping
• Hibernate - Table Per Hierarchy using XML File
• Hibernate - Table Per Hierarchy using Annotation
• Hibernate - Table Per Concrete Class using XML File
• Hibernate - Table Per Concrete Class Using Annotation
• Hibernate - Table Per Subclass Example using XML File
• Hibernate - Table Per Subclass using Annotation

Hibernate - Logging By Log4j Using Properties File

Logging is an essential aspect of application development, especially when dealing with frameworks like Hibernate. Log4j is a popular Java-based logging utility that integrates seamlessly with Hibernate. In this tutorial, we'll learn how to configure Hibernate logging using Log4j via a properties file.

1. Adding Dependencies:

You need to have the Log4j and Hibernate dependencies in your project. If you are using Maven, add the following dependencies to your pom.xml:

<!-- Hibernate Core -->
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-core</artifactId>
    <version>5.4.30.Final</version> <!-- use the latest version -->
</dependency>

<!-- Log4j API -->
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-api</artifactId>
    <version>2.14.1</version> <!-- use the latest version -->
</dependency>

<!-- Log4j Core (implementation) -->
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.14.1</version> <!-- use the latest version -->
</dependency>

2. Configure Log4j with a log4j.properties File:

Create a log4j.properties file in your src/main/resources directory with the following contents:

# Root logger option
log4j.rootLogger=INFO, stdout

# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

# Hibernate logging options
log4j.logger.org.hibernate=INFO

# Echo all SQL
log4j.logger.org.hibernate.SQL=DEBUG
log4j.logger.org.hibernate.type.descriptor.sql.BasicBinder=TRACE

This configuration will:

• Output log messages to the console.
• Set the default logging level for Hibernate to INFO.
• Print out the SQL statements Hibernate is executing (due to the DEBUG level on org.hibernate.SQL).

3. Configure Hibernate:

In your Hibernate configuration (hibernate.cfg.xml or persistence.xml), ensure that you have the following property set:

<property name="hibernate.show_sql">false</property>

By setting hibernate.show_sql to false, you're letting Log4j handle SQL logging rather than Hibernate's basic built-in mechanism.

4. Initialize Log4j:

If you are using a standalone application, Log4j should initialize itself using the log4j.properties file when your application starts up.

For web applications, ensure that the Log4j initialization runs when your web context starts. Most modern servlet containers will handle this automatically when they detect Log4j in the classpath.

5. Test It Out:

Run your application, perform some database operations using Hibernate, and observe the logging output in your console. You should see Hibernate's log messages and SQL statements being printed.

Conclusion:

Configuring Hibernate to use Log4j for logging via a properties file is straightforward. Proper logging is crucial for troubleshooting, performance tuning, and understanding the behavior of your application. Adjusting the logging levels as shown in the log4j.properties file allows you to get fine-grained control over the logging output, which can be invaluable in both development and production environments.

1. Log4j properties file for Hibernate logging:

   • Description: Create a Log4j properties file to configure logging settings for Hibernate. The file includes configurations for appenders, log levels, and other settings.
   • Code:

     # log4j.properties
     
     # Root logger option
     log4j.rootLogger=INFO, console, file
     
     # Console appender configuration
     log4j.appender.console=org.apache.log4j.ConsoleAppender
     log4j.appender.console.layout=org.apache.log4j.PatternLayout
     log4j.appender.console.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
     
     # File appender configuration
     log4j.appender.file=org.apache.log4j.RollingFileAppender
     log4j.appender.file.File=logs/hibernate.log
     log4j.appender.file.MaxFileSize=5MB
     log4j.appender.file.MaxBackupIndex=10
     log4j.appender.file.layout=org.apache.log4j.PatternLayout
     log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
     

2. Logging Hibernate SQL queries with Log4j:

   • Description: Enable logging of Hibernate SQL queries by adjusting the Log4j configuration. Set the log level for the specific Hibernate category to include SQL statements.
   • Code:

     # Enable SQL logging for Hibernate
     log4j.logger.org.hibernate.SQL=DEBUG