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    <p>Singleton guarantees single instance inside Spring container. That mean that you could have as many <code>singleton</code> instances as there are containers (even if they use the same JVM class loader). See <a href="http://static.springsource.org/spring/docs/3.2.1.RELEASE/spring-framework-reference/html/beans.html#beans-factory-scopes-singleton" rel="nofollow noreferrer">The singleton scope</a> and this answer for <a href="https://stackoverflow.com/questions/2637864/singleton-design-pattern-vs-singleton-beans-in-spring-container">Singleton Design Pattern vs. Singleton Bean</a> </p> <p>In your case you're instantiating two contexts - rootContext and servletContext and that were log statements are coming from.</p> <p>If you want to have single instance of every singleton - you could merge these two contexts.</p> <hr> <p>Small java class which illustrates such behavior(apologies for weird code formatting - wanted to make it more concise ):</p> <pre><code>package singleton; import java.util.UUID; import org.springframework.context.annotation.AnnotationConfigApplicationContext; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.stereotype.Component; public class AppMain { public static void main(String[] args) { final AnnotationConfigApplicationContext rootContext = new AnnotationConfigApplicationContext(); rootContext.register(AppRootContext.class); rootContext.refresh(); final AnnotationConfigApplicationContext servletContext = new AnnotationConfigApplicationContext(); servletContext.register(AppServletContext.class); servletContext.refresh(); final Singleton one = (Singleton) rootContext.getBean("singleton"); final Singleton andAnotherOne = (Singleton) servletContext.getBean("singleton"); System.out.println("Singletons are " + (one.ID.equals(andAnotherOne.ID) ? "equal" : "different")); } } @Component class Singleton {public String ID = UUID.randomUUID().toString();} @Configuration @ComponentScan(basePackages = { "singleton" }) class AppRootContext {} @Configuration @ComponentScan(basePackages = { "singleton" }) class AppServletContext {} </code></pre>
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    1. USPetro Semeniuk
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    1. COI'd add that the containers are essentially ClassLoader instances, so Singleton is respected *within a ClassLoader*
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      1. USAndrew Alcock
    2. COIt's true in general, but in this case both containers are instantiated using default constructor in the same thread and will use the same class loader(`Thread.getContextClassLoader()`). This behavior is inherited from `DefaultResourceLoader`. That said, even if spring containers share the same class loader you you'll get multiple instances of spring singleton.
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      1. USPetro Semeniuk
    3. COSorry, I was not clear. An implementation of the GoF Singleton will be a singleton across all containers in a ClassLoader, but you are right, that you get one object per container with singleton *scope*. Sorry for that.
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