What design patterns are used in Spring framework? [closed]

Answer 1

Factory Method patter: BeanFactory for creating instance of an object Singleton : instance type can be singleton for a context Prototype : instance type can be prototype. Builder pattern: you can also define a method in a class who will be responsible for creating complex instance.

Answer 2

Spring container generates bean objects depending on the bean scope (singleton, prototype etc..). So this looks like implementing Abstract Factory pattern. In the Spring's internal implementation, I am sure each scope should be tied to specific factory kind class.

Answer 3

Observer-Observable: it is used in ApplicationContext's event mechanism

Answer 4

Factory pattern is also used for loading beans through BeanFactory and Application context.

Answer 5

And of course dependency injection, or IoC (inversion of control), which is central to the whole BeanFactory/ApplicationContext stuff.

Answer 6

There are loads of different design patterns used, but there are a few obvious ones:

• Proxy - used heavily in AOP, and remoting.

• Singleton - beans defined in spring config files are singletons by default.

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

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Update following comments: For MVC, you might want to read the MVC Reference

Some obvious patterns in use in MVC:

• 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.