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>();

}

}

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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);

}

}