Spring Prototype : Singleton « Spring « Java Tutorial

1. Java Tutorial
2. Spring
3. Singleton

File: context.xml

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
"http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
    <bean id="prototypeClient"
          class="SpringPrototypeClient">
        <property name="message1" ref="message"/>
        <property name="message2" ref="message"/>
    </bean>

    <bean id="message" class="EmailMessage" singleton="false"/>
</beans>

File: Main.java

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

public class Main {
  public static void main(String[] z) {
    ApplicationContext context = new ClassPathXmlApplicationContext("context.xml", Main.class);
    SpringPrototypeClient client = (SpringPrototypeClient) context.getBean("prototypeClient");
    client.run();
  }

}
class SpringPrototypeClient {
  private Message message1;
  private Message message2;

  public void run() {
      System.out.println("Message1 " + this.message1.toString());
      System.out.println("Message2 " + this.message2.toString());
      System.out.println("Messages == " + (this.message1 == this.message2));
  }

  public void setMessage1(Message message1) {
      this.message1 = message1;
  }

  public void setMessage2(Message message2) {
      this.message2 = message2;
  }
}
abstract class Message {

  public Message makeCopy() {
    try {
      return this.getClass().newInstance();
    } catch (InstantiationException e) {
      return null;
    } catch (IllegalAccessException e) {
      return null;
    }
  }
}

class EmailMessage extends Message {

  @Override
  public String toString() {
    return "EmailMessage";
  }

}

28.11.Singleton
	28.11.1.	Prototype Singleton
	28.11.2.	BeanFactory PreInstantiate Singletons Integration
	28.11.3.	Spring Prototype
	28.11.4.	Singleton Scope And Prototype Scope