Two, Spring introduced the concept and project

A, Spring Core Concepts

1, the reverse control (IoC) and dependency injection (DI)

concept

IoC: A creation and management of external technical term component depends.
For example: To manufacture a pen Wang, Wang made themselves previously required, Ioc this work is to let third Fang Xiaoming (container: such as factories) to produce and manage.
DI: A method of operating when an object (including attributes) through the container, to another object of art. IoC relation to DI corresponding to sides of a coin, so that they are integral relationship on both sides, in the context of Spring, these terms are interchangeable concepts, without any loss
of illustration: by a third Fang Xiaoming Wang ( containers: the plant) for producing a pencil (object), and then to use when Ronaldinho, via the third Fang Xiaoming transferred to Ronaldinho, rather than directly to Wang Ronaldinho.

Advantages and disadvantages of using IoC / DI's

Advantage

1. Reducing adhesion (code reuse)
2. Simplify the application configuration (change from mysql to oracle database, simply suitably arranged business object dependency)
3. Dependencies can be managed in a single common storage (the dependency centralized management, so that the management simpler and less error)
4. Improve testability (test requires only simple business code, and the test can be layered (DAO layer, service layer, domain layer, Controller layer), make testing easier definition)
5. Develop good application design (reducing the workload, focus on your business, not the frame, and more use of the interface in order to achieve the decoupling effect)

Shortcoming

• For people not familiar with the code of speaking, DI / IoC hard for them to know which achieve the objects of a particular dependency that connection.

2, additional features of the Spring 5

• Support Java 9
• Spring implemented using Aspect Oriented Programming (AOP: Aspect Oriented Programming)
  • Support for AspectJ pointcut expression style
  • Support @AspectJ comment (Spring 3.2 start)
  • DI implementation supports aspects in AspectJ
  • A weaving when supporting Spring judge by reason of loading cationContext
• Spring Expression Language
  • From Spring 3.0, Spring introduced the expression language SpEL (Spring Exprssion Language),
  • Is a standard expression language, other alternative expression language EL (Expression Language), to make a unified expression language UEL (Unified Expression Language).
• Spring validation Validation, starting Spring 4.0, JSR-349 (Bean Validation) supported version 1.1
• In the Spring data access: The JDBC API has been simplified package of (Sql and NoSql database access, the proposed research Spring Data projects)
• Spring objects / XML mapping (conversion JavaBean and XML)
• Management (programmatic and declarative transaction control)
• Simplify and integration with JEE
• MVC Web layer (Spring WebFlux and Spring MVC)
• WebSocket support (for defined between a client and a server through a persistent connection member API)
• Remote support (RMI, JAX-WS, JMS, AMQP, REST, etc.)
• Mail Support
• Job scheduling support
• Dynamic scripting support (Groovy, Jruby and BeanShell)
• Simplifies exception handling ( non checked exception unchecked exceptions: RuntimeException and its subclasses, and error (Error) )

Two, Spring project and alternatives

1, Spring projects

1. Spring Tool Suite (Spring IDE and Spring Tool Suite (STS) tool )
2. Spring Security (offers comprehensive support for web applications and method-level security)
3. Spring Boot (simplified create work items)
4. Spring Batch and Integration (Spring Batch and Spring Integration)
5. Other (Spring XD, Android for Spring, Spring Mobile, Spring Social and Spring AMQP, more message information )

2, Spring alternatives

1. JBoss Seam framework (Spring and the main difference is entirely based on JBoss JEE standard development)
2. Google Guice
3. PicoContainer
4. JEE 7 container

Reproduced in: https: //www.jianshu.com/p/26dd03e17d44