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:”