Spring : Design Patterns Used in Java Spring Framework

Dependency injection/ or IoC (inversion of control) – Is the main principle behind decoupling process that Spring does

Factory – Spring uses factory pattern to create objects of beans using Application Context reference

// Spring uses factory pattern to create instances of the objects
BeanFactory factory = new XmlBeanFactory(new FileSystemResource("spring.xml"));
Triangle triangle = (Triangle) factory.getBean("triangle");
triangle.draw();

Proxy – used heavily in AOP, and remoting.

Singleton – by default, beans defined in spring config file (xml) are only created once. No matter how many calls were made using getBean() method, it will always have only one bean. This is because, by default all beans in spring are singletons.
This can be overridden by using Prototype bean scope.Then spring will create a new bean object for every request.

Model View Controller – The advantage with Spring MVC is that your controllers are POJOs as opposed to being servlets. This makes for easier testing of controllers. One thing to note is that the controller is only required to return a logical view name, and the view selection is left to a separate ViewResolver. This makes it easier to reuse controllers for different view technologies.

Front Controller – Spring provides DispatcherServlet to ensure an incoming request gets dispatched to your controllers.

View Helper – Spring has a number of custom JSP tags, and velocity macros, to assist in separating code from presentation in views.

Template method – used extensively to deal with boilerplate repeated code (such as closing connections cleanly, etc..). For example JdbcTemplate, JmsTemplate, JpaTemplate.

Reference – http://stackoverflow.com/questions/755563/what-are-the-design-patterns-which-used-in-spring-framework