for s[ring student take this and use i hope it is very usefull for you people

1. Spring AnnotationSupport :-
Spring2.0 has a verylittle supportto annotation,whenitcomestospring2.5 , it has extendedit's
frameworktosupportvariousaspectsof springdevelopmentusingannotations.Inspring3.0 it
startedsupportingjavaconfigprojectannotationsaswell.
In Spring2.0 it has added@Repositoryand@Requiredannotations.
In Spring2.5 it has addedfewmore annotations@Autowired,@Qualifierand@Scope.
alongwithabove annotation'sinspring2.5 sterotype annotations@Component,@Controller,
@Service .
In Spring3.0 fewmore annotationshasbeenaddedlike
@Lazy,@Bean,@Configuration,@DependsOn,@Valueetc..
In additiontospringbasedmetadataannotationsupport,ithasstartedadoptionJSR-250javaconfig
projectannotationslike @PostConstruct,@PreDestory,@Resource ,@Injectand@Namedetc...
@Requiredannotation :- In spring1.x onwordswe have dependency
check.fora beanif youwant to detectunresolveddependenciesof abean,youcanuse dependency
check.In Spring2.0 ithas introduced anannotation@Required .byusingthisannotationyoucan
make , a particularpropertyhas beensetwithvalue (OR) not.inspring2.5 @Requiredannotation
and dependency -checkcompletlyremoved.
@Autowired:- annotationtoautowire bean onthe settermethod,constructor(OR) afiled.
Example :-
EmployeeService.java
publicclassEmployeeService{
@Autowired
private EmployeeDAO empDao;
}
EmployeeDAO.java
publicclassEmployeeDAO{
@Autowired
private DataSource dataSource;
}

2. The @Autowired Annotationishighlyflexible andpowerful,andbetterthan<autowire>attribute in
bean configurationfile.
Aboutthe @Autowiredannotationtogive anintimationtospringIOCcontainerwe canuse
<context:annotation-config/> inspringfile.
Note :
By default,the @Autowiredwill performthe dependencycheckingtomake sure the propertyhas
beenwiredproperly.WhenSpringcontainer can'tfinda matchingbeanto wire,itwill throw an
Exception.if youwanttodisable the dependencycheckingfeature thenwe canuse the "required"
attribute of @Autowiredannotation.if the requiredattributevalue isfalsethenthe dependency-
checking is disabled.elsedependency -checkingisenabled.the defaultvalue of requiredattrbute is
true.
Example :-
publicclassEmployeeService{
@Autowired(required=false)
private EmployeeDAOempDao;
}
@Qualifier:-
for example,Inbeanconfigurationfile for EmployeeDAO bean two configuration'sare there.
<beans>
<beanid="empDao1"class="com.nareshit.dao.EmployeeDAO"/>
<beanid="empDao2"class="com.nareshit.dao.EmployeeDAO"/>
</beans>
In EmployeeService class
publicEmployeeService{
@Autowired
private EmployeeDAO employeeDao;
}
here employeeDao1(OR) employeeDao2whichbeanisrequiredto injectdon’tknow by the
containersoContainerWill rise AnException.ToSolve thisproblemand toinjecta particularbean
i,e employeeDao1(OR) employeeDao2 we can use @Qualifierannotation

3. The @Qualifierannotationisused to control whichbeanshouldbe autowire onafield.
Example:-
publicclassEmployeeService{
@Autowired
@Qualifier("emDao1")
private EmployeeDAOempDao;
}
DAO.java
package com.nareshit;
publicclass DAO{
publicvoid daoMethod(){
System.out.println("DAOMethod");
}
}
Service.java
package com.nareshit;
import org.springframework.beans.factory.annotation.Autowired;
publicclass Service {
@Autowired
private DAOdao;
publicvoid serviceMethod() {
System.out.println("serviceMethod");
dao.daoMethod();
}
}

4. myBeans.xml
<beansxmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:annotation-config/>
<beanid="dao"class="com.nareshit.DAO"/>
<beanid="service" class="com.nareshit.Service" />
</beans>
Test.java
package com.nareshit.client;
importorg.springframework.context.ApplicationContext;
importorg.springframework.context.support.ClassPathXmlApplicationContext;
importcom.nareshit.Service;
publicclassTest{
publicstaticvoidmain(String[] args){
ApplicationContextcontext=
newClassPathXmlApplicationContext("com/nareshit/xml/myBeans.xml");
Service service=(Service)context.getBean("service");
service.serviceMethod();
}
}
Stereotype Annotations:
In Spring there are 4 Stereotype Annotations
1)@Component: Indicatesanauto scan component.
2) @Service – IndicatesaService component in the businesslayer/serviceLayer.
3) @Repository – IndicatesDAOcomponent inthe persistence layer.
4) @Controller– Indicatesacontroller componentinthe Controllerlayer.
Example 1 :-
@Component
public classEmployeeService{
}
Example 2 :-

5. @Component(“empService”)
public classEmployeeService{
}
@Component Annotationisindicatingtothe containerEmployeeService isclassisan auto scan
component.
About the Stereotype annotationtogive anintimationtothe containerwe canuse
<context:component-scanbase-package=”com.nareshit”/>inspringconfigurationfile.
DAO.java
package com.nareshit;
import org.springframework.stereotype.Component;
@Component
publicclass DAO{
publicvoid daoMethod(){
System.out.println("DAOMethod");
}
}
Service.java
package com.nareshit;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
@Component("service")
publicclass Service {
@Autowired
private DAOdao;
publicvoid serviceMethod() {
System.out.println("serviceMethod");
dao.daoMethod();
}
}

6. myBeans.xml
<beansxmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scanbase-package="com.nareshit">
</context:component-scan>
</beans>
Test.java
package com.nareshit.client;
importorg.springframework.context.ApplicationContext;
importorg.springframework.context.support.ClassPathXmlApplicationContext;
importcom.nareshit.Service;
publicclassTest{
publicstaticvoidmain(String[] args){
ApplicationContextcontext=
newClassPathXmlApplicationContext("com/nareshit/xml/myBeans.xml");
Service service=(Service)context.getBean("service");
service.serviceMethod();
}
}
The @Repository,@Service and@Controller are annotatedwith @Componentannotation
internally.the Three annotation'salso componentType annotations.
to increase the readability of the programwe can use @Service annotationinService Layer
@Repositoryannotation inDAO/Persistence Layerand @ContollerannotationinControllerLayer
Insteadof @Componenttype annotation.
Example :
EmployeeService.java
@Service
publicclassEmployeeService{
}
EmployeeDAO.java
@Repository
publicclassEmployeeDAO{

7. }
@Value Annotation
@Value Annotationisgivenspring3.0version.Itisusedto injectthe valuesonsimple type
dependencies
publicclass CustomerBean{
@Value(“1001”)
private intcustomerId;
@Value(“sathish”)
private StringcustomerName;
}
working with @Configurationand @Bean :-
Insteadof declaringaclass as springbeanina configurationfile,youcandeclare itina class.The
classin whichyouwantto provide the configurationaboutotherbeans,thatclassiscalled
configurationclassandyouneedtoannotate with@Configuration.
In thisclassyou needtoprovide the methodswhichare responsible forcreatingobject'sof your
beanclasses,these methodshastobe annotatedwith@Bean.
Example :-
Service.java
package com.nareshit;
publicclass Service {
private DAOdao;
publicvoid setDao(DAOdao) {
this.dao= dao;
}

8. publicvoid serviceMethod() {
System.out.println("serviceMethod");
dao.daoMethod();
}
}
DAO.java
package com.nareshit;
publicclass DAO{
publicvoid daoMethod(){
System.out.println("DAOMethod");
}
}
MyBeans.java
package com.nareshit.config;
importorg.springframework.beans.factory.annotation.Autowire;
importorg.springframework.context.annotation.Bean;
importorg.springframework.context.annotation.Configuration;
importcom.nareshit.DAO;
importcom.nareshit.Service;
@Configuration
publicclassMyBeans{
@Bean(name="service",autowire=Autowire.BY_TYPE)
publicService service(){
returnnewService();
}
@Bean(name="dao")
publicDAOdao(){
return newDAO();
}
}
Test.java
package com.nareshit.client;

9. import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.nareshit.Service;
publicclass Test{
publicstatic voidmain(String[]args){
ApplicationContextcontext=
new AnnotationConfigApplicationContext(com.nareshit.config.MyBeans.class);
Service service=(Service)context.getBean("service");
service.serviceMethod();
}
}
@Inject :-
@InjectisJ2ee specificannotation,usedforInjectiong/autowiringone classintoanother.
Thisis similarto@Autowiredspringannotation.Butthe difference between@Autowiredsupports
requiredattribute where @Injectdoesn'thas it.@Injectalsoinjectsabeanintoanotherbeanas
similarto@Autowired.itispresentinjavax.injectpackage.
Example :
EmployeeService.java
publicclassEmployeeService{
@Inject
private EmployeeDAOempDao;
}
EmployeeDAO.java
publicclass EmployeeDAO{

10. @Inject
private DataSource dataSource;
}
@Named it isa J2EE annotationandIt is similarto@Qualifier springAnnotation
@Resource isa J2EE annotationsimilarto@Injectbutitwill performthe injectionbyusingbyName
rules