Spring Tutorial 05 - ApplicationContext and Property Initialization

Introduction to Application Context in Spring

Overview of Application Context

• The tutorial introduces the concept of ApplicationContext, which is an extension of the BeanFactory used for object instantiation in Spring.

• Unlike BeanFactory, ApplicationContext offers additional functionalities such as event notification and Aspect-Oriented Programming (AOP).

• It is recommended to use ApplicationContext over BeanFactory unless resources are critically limited due to similar performance costs.

Transitioning from Bean Factory to Application Context

• The speaker demonstrates how to change code from using a BeanFactory to an ApplicationContext.

• An example implementation, ClassPathXmlApplicationContext, allows loading XML configuration directly from the classpath without needing a file system resource.

Configuring Triangle Object with Spring

Setting Up Configuration

• The tutorial discusses moving the XML configuration file (spring.xml) into the classpath for proper access during application runtime.

• The speaker confirms successful instantiation of a triangle object after adjusting the configuration file location.

Enhancing Triangle Class Functionality

• A member variable named "type" is introduced in the triangle class, allowing preset values during object instantiation.

• By modifying the XML blueprint, users can prefill properties like "type" when creating objects through Spring.

Defining Properties in spring.xml

Blueprint Configuration

• The speaker explains how to define properties within the XML configuration by adding property tags that specify names and values.

• An example is provided where "type" is set as "equilateral triangle," demonstrating how Spring uses this information during object creation.

Resulting Behavior of Triangle Object

• When requesting a triangle object, Spring will instantiate it according to defined properties, ensuring that preset values are automatically assigned.

• Modifications made in methods allow for displaying predefined attributes; running this results in output confirming that an equilateral triangle has been drawn.