Spring_App_9_Bean_Initialization_Distruction_using_custom_initialization_distruction

package com.amit.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import amit.com.beans.HelloBean;

public class Test {

public static void main(String[] args)
{
     ApplicationContext context = new ClassPathXmlApplicationContext("applicationConfig.xml");
     HelloBean bean = (HelloBean) context.getBean("hb");
     System.out.println(bean.sayHello());

}

}

=====================================================================

package amit.com.beans;

public class HelloBean 

{

HelloBean()

{

System.out.println("Object Creation.......");

}

public void initialize()

{

System.out.println("Initialization......");

}

public void destroy()

{

System.out.println("Destruction......");

}

public String sayHello()

{

return "Hello User";

}

}

=====================================================================

<?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="hb" class ="amit.com.beans.HelloBean" init-method="initialize" destroy-method="destroy"></bean>

</beans>        

====================================================================

Spring_App_8.3_BeanLifeCycleUsingStaticFactoryMethod

package com.amit.bean;

public class HelloBean
{

private HelloBean()    // here private method is getting accessed due to Reflection
{
System.out.println("Constructor: Bean Object Creating...");
}

public static HelloBean getInstance()  //---getInstance()  (use it in config file)
{
System.out.println("Bean instantiation through static factory method");
return new HelloBean();
}
public String sayHello()
{
return "Hello User";
}

}

=====================================================================

package com.amit.test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.amit.bean.HelloBean;

public class Test {

public static void main(String[] args) 

{

  ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

  HelloBean b = (HelloBean)context.getBean("helloamit");

  System.out.println(b.sayHello());

}

}

====================================================================

<?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="helloamit" class="com.amit.bean.HelloBean"/>   --> <!-- Use this for normal instantiation -->

<bean id="helloamit" class="com.amit.bean.HelloBean" factory-method="getInstance"/>   <!-- Use this for static factory method -->

</beans>        

Spring_App_8.2_BeanLifeCycleUsingInstanceFactoryMethod

package com.amit.beans;

public class HelloBean
{
/*
* HelloBean() { System.out.println("HelloBean object created......"); }
*/
  public String sayHello()
  {
  return "Hello User";
  }
}

=====================================================================

package com.amit.factory;

import com.amit.beans.HelloBean;

public class HelloBeanFactory     // Factory class...configure it 

{

HelloBeanFactory()

{

System.out.println("HelloBeanFactory Object created.....");

}

public HelloBean getHelloBeanInstance() //Factory Method...configure it

{

System.out.println("Bean instantiation through Instance factory Method...");

return new HelloBean(); 

}

public String getMsg()

{

return "msg from HelloBeanFactory";

}

}

=====================================================================

package com.amit.test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.amit.beans.HelloBean;

import com.amit.factory.HelloBeanFactory;

public class Test 

{

public static void main(String[] args) 

{

  ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

  HelloBean hb = (HelloBean)context.getBean("helloBean");

  String ss = hb.sayHello();

  System.out.println(ss);

  

  HelloBeanFactory hbf = (HelloBeanFactory)context.getBean("helloBeanFactory");

  System.out.println(hbf.getMsg());

}

}

Spring_App_8.1_BeanLifeCycleUsingConstructor

package com.amit.bean;

//private class HelloBean  --> we can keep any scope (public , private)
public class HelloBean
{
public HelloBean()               //--> Parameterized constructor not allowed
{
System.out.println("...Bean Instantiation...");
}
public String sayHello()
{
return "Welcome";
}
}

====================================================================

package com.amit.test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.amit.bean.HelloBean;

public class Test {

public static void main(String[] args) 

{

  ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

  HelloBean bean = (HelloBean)context.getBean("helloBean");

  String msg = bean.sayHello();

  System.out.println(msg);

}

}

====================================================================

<?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="helloBean" class="com.amit.bean.HelloBean">

</bean>

        

</beans>        

====================================================================

Spring_App_8_JavaConfig

package com.amit.beans;

public class HelloBean
{
public HelloBean()
{
System.out.println("HelloBean Loanding....");
}
public String sayHello()
{
return "Message from HelloBean";
}

}

===================================================================

package com.amit.beans;

public class WelcomeBean  // Class of Bean needs to be mentioned in BeanConfiguration

{

public WelcomeBean()

{

System.out.println("WelcomeBean Loading.....");

}

public String getMsg() 

{

return "Message 1 from WelcomeBEAN";

}

}

====================================================================

package com.amit.config;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import com.amit.beans.HelloBean;

import com.amit.beans.WelcomeBean;

@Configuration   // optional

public class BeanConfiguration 

{

@Bean        //returned object in bean therefore declare @Bean

public WelcomeBean welcome_Bean() // id = welcome_Bean

{

return new WelcomeBean();

}

@Bean

public HelloBean helloBean()

{

return new HelloBean();

}

}

=====================================================================

package com.amit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import com.amit.beans.HelloBean;

import com.amit.beans.WelcomeBean;

import com.amit.config.BeanConfiguration;

public class Test {

public static void main(String[] args) 

{

  ApplicationContext context = new AnnotationConfigApplicationContext(BeanConfiguration.class);

  WelcomeBean bean = (WelcomeBean)context.getBean("welcome_Bean");  //welcomeBean act like id (in classpathxmlApplicationcontext)

  String s = bean.getMsg();

  System.out.println("MSG: "+s);

  

  HelloBean bean2 = (HelloBean)context.getBean("helloBean");

  String s2 = bean2.sayHello();

  System.out.println("MSG: "+s2);

  

  

  

  

}

}

======================================================================

Spring_App_7_CustomScope

package com.amit.beans;

public class HelloBean
{
public HelloBean()
{
System.out.println("Hello bean created....");
}

}

=========================================================================

package com.amit.customScope;

import java.util.HashMap;

public class MyThreadLocal extends ThreadLocal 

{

@Override

protected Object initialValue()  //executed when we call getMethod() but no set value

{

  return new HashMap<String,Object>();

}

}

=======================================================================

package com.amit.customScope;

import java.util.HashMap;

import org.springframework.beans.factory.ObjectFactory;

import org.springframework.beans.factory.config.CustomScopeConfigurer;

import org.springframework.beans.factory.config.Scope;

public class ThreadScope implements Scope 

{

MyThreadLocal threadlocal = new MyThreadLocal();

HashMap<String,Object> scope = null; // to get scope object

@Override

public Object get(String name, ObjectFactory<?> objFactory)  //return bean object (available in the thread scope), if not available create a new bean object keep it in scope and return it.

{ //ObjectFactory class is in Spring used to create Bean Object

scope = (HashMap<String,Object>) threadlocal.get();  //calls initialValue() if no object is created

Object obj = scope.get(name);     // to check if it return object 

         if(obj == null)

         {

        obj = objFactory.getObject();

        scope.put(name, obj);                                  //keep obj in scope hashmap

         } 

return obj;

}

@Override

public String getConversationId() // to get id for bean e.g session id

{

return null;

}

@Override

public void registerDestructionCallback(String arg0, Runnable arg1) //when bean destroyed

{

}

@Override

public Object remove(String name) //to remove bean obj from scope

{

  Object obj = scope.remove(name);

return obj;

}

@Override

public Object resolveContextualObject(String arg0) // Resolves --> if 1 key is associated with multiple context object 

{

return null;

}

}

========================================================================

<?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="helloBean" class ="com.amit.beans.HelloBean" scope="thread"/>

<bean id="customThreadScope" class ="com.amit.customScope.ThreadScope" />

<bean id ="customScopeConfigurer" class="org.springframework.beans.factory.config.CustomScopeConfigurer">

<property name="scopes">

    <map>

         <entry key="thread" value-ref = "customThreadScope">

         </entry>

    </map>

</property>

</bean>

</beans>        

========================================================================

package com.amit.test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.amit.beans.HelloBean;

public class Test {

public static void main(String[] args) 

{

  ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

  HelloBean bean1 = (HelloBean)context.getBean("helloBean");

  System.out.println("bean1 "+bean1);

  

  HelloBean bean2 = (HelloBean)context.getBean("helloBean");

  System.out.println("bean2 "+bean2);

}

}

Spring_App_6

package com.amit.Test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.amit.Beans.HelloBean;

public class Test {

public static void main(String[] args)
{
ApplicationContext context = new ClassPathXmlApplicationContext("beanconfig.xml");

HelloBean bean = (HelloBean)context.getBean("tesingscope");
System.out.println("1>>"+bean);
System.out.println("1>>"+bean);

HelloBean bean2 = (HelloBean)context.getBean("testingscope2");
System.out.println("2>>"+bean2);
System.out.println("2>>"+bean2);

HelloBean bean3 = (HelloBean)context.getBean("testingscope2");
System.out.println("3>>"+bean3);
System.out.println("3>>"+bean3);


bean.setName("Amit");
String name = bean.getName();
System.out.println(name);

}

}

//--- for prototype
/*
 * 1>>com.amit.Beans.HelloBean@3cbbc1e0
 * 1>>com.amit.Beans.HelloBean@3cbbc1e0
 * 2>>com.amit.Beans.HelloBean@35fb3008
 * 2>>com.amit.Beans.HelloBean@35fb3008
 * 3>>com.amit.Beans.HelloBean@7225790e
 * 3>>com.amit.Beans.HelloBean@7225790e
 * Amit
 */
//--- for singleton
/*
1>>com.amit.Beans.HelloBean@3cbbc1e0
1>>com.amit.Beans.HelloBean@3cbbc1e0
2>>com.amit.Beans.HelloBean@35fb3008
2>>com.amit.Beans.HelloBean@35fb3008
3>>com.amit.Beans.HelloBean@35fb3008
3>>com.amit.Beans.HelloBean@35fb3008
Amit
* Amit
*/


=======================================================================
package com.amit.Beans;

public class HelloBean
{
private String name;

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}


}

=======================================================================

<?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="tesingscope" class ="com.amit.Beans.HelloBean" scope="singleton">

</bean>

<!--<bean id ="testingscope2" class="com.amit.Beans.HelloBean" scope="prototype"> -->

<bean id ="testingscope2" class="com.amit.Beans.HelloBean" scope="singleton">

</bean>

        

</beans>