SPRINGIOC of Technical Summary

1) SPRINGIOC Core Simulation implementation

Idea: When initializing a spring container, read the defined bean information from the configuration file and deposit it into the spring container based on the configuration property initialization.

When a bean is needed, it is obtained directly from the container through the ID.

Steps:

A) Create a Java project that requires a dependency package (primarily used to parse XML files) such as:

b) First simulate spring to define two simple beans in the configuration file My-ioc.xml, as follows:

c) Follow the above ideas to simulate spring implementation of our own IOC container Myioccontext, implemented as follows:

1. public class Myioccontext {

3. Private final map<string, object> beanmap = new hashmap<string, object> ();

5. Public Myioccontext (String fileName) {

6. Init (fileName);

7. }

9. private void init (String fileName) {

11. }

13. Public Object Getbean (String ID) {

14. return Beanmap.get (ID);

15. }

16. }

Where Init is implemented as follows:

d) Test:

1. public class Myioctest {

3. Private Myioccontext CTX = null;

5. @Before

6. public void SetUp () throws Exception {

7. CTX = new Myioccontext ("My-ioc.xml");

8. }

10. @Test

11. public void Testioc () throws Exception {

12. Hello hello = (hello) ctx.getbean ("Hello");

13. Hello.say ("My IOC Context");

14. }

15. }

The result is:

At this point, the core implementation of the IOC container is complete.

2) Spring Dependent injection method

A) Manual injection

• Constructor injection.
  

• Property setter injection.
  

• Use field injection (for annotation mode) as follows:
  

1. @Autowired: Injecting by type

2. @Resource: Injected by name if it fails and then injected by type. If name is specified, it is injected by name only.

b) Automatic injection

Configuration in XML, <bean id= "" class= "" autowire= "Bytype"/>

SPRINGIOC of Technical Summary