Spring Core

Open source
Lightweight.
Written in java.
Framework of frameworks.
Enterprise and internet support.
Provides pattern and structure for java.
It manages object instances (Application context).
Used to make java application loosely coupled (easy to change).

Life Cycle Method of Beans -------------- >>

Spring provide two important methods to every bean.
public void init (): for initialization code.
public void destroy(): for cleanup code.

• Life Cycle

Bean object created with metadata of configuration XML file.
Set properties values.
Init() method called.
Read and use the beans.
Destroy() method called.
Bean object ended.

Configuration Technique

o XML

o Spring interface

Initializing Bean: for init() method
Disposable Bean: for destroy() method

o Annotation.

@PostConstruct: for init() method
@PreDestroy: for destroy() method.
Note that both the @PostConstruct and @PreDestroy annotations are part of Java EE. If you are using java 9 and above, add an additional dependency in “pom.xml” to use these annotations.

Annotations are disabled by default, to enable annotations

All annotations:“context:annotation-config”
Only @PostConstruct and @PreDestroy:”