Groovy Bean Configuration in Spring 4
- Pulkit Pushkarna
- Currently working for ToTheNew as Senior Software Enigineer.
- Over 2 years of experience in Grails and Spring.
- Love to play with Java 8, Groovy and Spring.
A bit about me
Pulkit Pushkarna
Agenda
- Brief Intro of Spring and Groovy
- Configuring Spring beans in groovier way
- Aliasing a bean
- Setting values of instance variables
- Define the scope of the bean
- Lifecycle callbacks
- Bean Definition Inheritance
- Setting values for reference type
- Annotation config
- AOP configuration
What is Spring?
Spring is described as lightweight framework for building java applications.
The core of Spring Framework is based on the principle of Inversion of Control (IOC).
IOC is a technique that externalizes the creation and management of Component dependencies.
Spring acts like a container which provides instances of your application classes with all the dependencies they need.
A Spring managed resource is referred to as bean.
What is groovy ?
Groovy is a powerful, optionally typed and dynamic language, with static-typing and static compilation capabilities, for the Java platform aimed at improving developer productivity
- Flat learning curve
- Smooth Java Integration
- Domain Specific Language
- Powerful Features like Closures, Functional Programming, Type Inferencing etc
Configuring a bean in Spring container
XML Configuration
Groovy Configuration
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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.xsd">
<bean class="com.spring.demo.Employee"/>
</beans>
beans {
employee(Employee)
}
Getting a bean from Spring container
XML Configuration
ApplicationContext applicationContext=new ClassPathXmlApplicationContext("config.xml");
Employee employee=applicationContext.getBean("employee",Employee.class);
employee.display();
Groovy Configuration
ApplicationContext applicationContext=new GenericGroovyApplicationContext("classpath:config.groovy");
Employee employee=applicationContext.getBean("employee",Employee.class);
employee.display();
Aliasing a bean
XML Configuration
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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.xsd">
<bean id="employee" class="com.spring.demo.Employee"/>
<alias name="employee" alias="employeeAlias"/>
</beans>
beans{
employee(Employee)
registerAlias("employee","employeeAlias")
}
Groovy Configuration
Setting values of instance variables
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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.xsd">
<bean id="employee" class="com.spring.demo.Employee">
<property name="age" value="27"/>
<property name="name" value="Spring"/>
</bean>
</beans>
beans{
employee(Employee){
age=27
name="Groovy"
}
}
XML Configuration
Groovy Configuration
beans {
employee(Employee, age:24, name:"Groovy")
}
Defining scope of a bean
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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.xsd">
<bean id="employee" class="com.spring.demo.Employee" scope="singleton">
<property name="name" value="Spring"/>
<property name="age" value="27"/>
</bean>
</beans>
XML Configuration
Groovy Configuration
beans{
employee(Employee){ bean->
bean.scope = "singleton"
name="Groovy"
age=26
}
}
Lifecycle Callback
XML Configuration
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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.xsd">
<bean id="employee" class="com.spring.demo.Employee" init-method="init"
destroy-method="destroy">
<property name="name" value="Spring"/>
<property name="age" value="27"/>
</bean>
</beans>
Groovy Configuration
beans{
employee(Employee){ bean->
bean.initMethod = "init"
bean.destroyMethod = "destroy"
name="Groovy"
age=26
}
}
Bean Definition Inheritance
XML Configuration
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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.xsd">
<bean id="parentBean" class="com.spring.demo.Employee">
<property name="name" value="Default"/>
</bean>
<bean id="employee" class="com.spring.demo.Employee" parent="parentBean" >
<property name="name" value="Spring"/>
<property name="age" value="27"/>
</bean>
</beans>
Groovy Configuration
beans{
parentBean(Employee){
name="Default"
}
employee(Employee){ bean->
bean.parent="parentBean"
name="Groovy"
age=26
}
}
Setting Value for Reference type
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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.xsd">
<bean id="address" class="com.spring.demo.Address">
<property name="city" value="Delhi"/>
<property name="country" value="India"/>
</bean>
<bean id="employee" class="com.spring.demo.Employee">
<property name="address" ref="address"/>
<property name="name" value="Spring"/>
<property name="age" value="27"/>
</bean>
</beans>
beans{
address(Address){
city="Mumbai"
country="India"
}
employee(Employee){
address=ref('address')
name="Groovy"
age=26
}
}
XML Configuration
Groovy Configuration
Annotation config
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<context:annotation-config/>
<bean id="address" class="com.spring.demo.Address">
<property name="city" value="Delhi"/>
<property name="country" value="India"/>
</bean>
<bean id="employee" class="com.spring.demo.Employee">
<property name="name" value="Spring"/>
<property name="age" value="27"/>
</bean>
</beans>
XML Configuration
beans{
xmlns([context:'http://www.springframework.org/schema/context'])
context.'annotation-config'()
address(Address){
city="Mumbai"
country="India"
}
employee(Employee){
address=ref('address')
name="Groovy"
age=26
}
}
Groovy Configuration
Collection Initialization
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
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.xsd">
<bean id="employee" class="com.spring.demo.Employee">
<property name="list">
<list>
<value>1</value>
<value>2</value>
<value>3</value>
</list>
</property>
<property name="set">
<set>
<value>1</value>
<value>2</value>
</set>
</property>
<property name="map">
<map>
<entry key="1" value="One"/>
<entry key="2" value="Two"/>
</map>
</property>
</bean>
</beans>
XML Configuration
beans{
employee(Employee){
list=[1,2,3,4]
set=[1,2]
map =[1:"One",2:"Two"]
}
}
Groovy Configuration
Importing beans from XML config
beans{
importBeans("classpath:config.xml")
}
AOP Configuration
beans{
xmlns([aop:"http://www.springframework.org/schema/aop"])
aop.'aspectj-autoproxy'()
}
Groovy Bean Configuration
By Pulkit Pushkarna
Groovy Bean Configuration
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