This document discusses the Spring framework and dependency injection. It explains that Spring uses dependency injection to configure classes by passing their dependencies from outside the class rather than having the class create dependencies directly. This allows classes to be more independent and testable. It provides an example of how the Spring framework uses annotations and a Spring injector to configure classes by injecting their dependencies rather than the classes creating dependencies internally.

2. Tác giả
• Rob Johnson
• Based on his book : Expert One-on-One J2EE
Design

3. What’s Spring
• Java Application Framework
• Spring core build on Dependency Injection
Pattern
• Many modules

5. Dependency Injection
• A class should not configure its dependencies
statically but should be configured from
outside
• If a class directly creates an instace of anohter
class via the new operator, it cannot be used
(and tested) independently

6. Problem
class DAOUser{
private DataSource dataSource
private DAOUser(){
dataSource = new MySQLDataSource();
datsSource.set(..some..properties);
}
}
DAOUser MySQLDataSource

7. Constructor Injection
class DAOUser{
private DataSource dataSource
private DAOUser(DataSource dataSource){
this.dataSource = dataSource
}
}
Easier to test
DAOUser DataSource

8. Injection
class DAOUser{
private DataSource dataSource
private DAOUser(DataSource dataSource){
this.dataSource = dataSource
}
}
OR
class DAOUser{
private DataSource dataSource
private void setDataSource(DataSource dataSource){
this.dataSource = dataSource
}
}
DAOUser DataSource

9. Injector 
class DAOInjector{
public void inject(){
DataSource dataSource = new DataSource();
DAOUser daoUser = new DAOUser(dataSource);
}
}
DAOUser DataSource
DAOInjector

10. Injector in Spring
class DAOUser{
@Autowired
private DataSource dataSource;
//setter for dataSource
...
}
@Component
class MySQLDataSource extends DataSource{
}

11. Demo

12. SPRING WEBSERVICE

13. Spring webservice

14. Spring Security

15. Demo