Spring understanding

Brief introduction

• Decouple code, enterprise-class development of the complexity of the problem: the degree of coupling
• System sub-codes:
  • Main business logic
    • Bank business
    • Insurance Business
    • ...
  • System level business logic, cross traffic
    • eg.JDBC
      1. Load the driver
      2. Create a connection
      3. Open affairs
      4. SQL operations
      5. Commit the transaction
      6. Connection release
• Glue framework
• Layered Java SE / EE full-stack (stop) a lightweight open source framework

Spring will be decoupled divided into two categories:

• IoC - Inversion of Control

  Objects to be used by the Spring container unified management
  eg.UserService userService = new UserServiceImpl (); ----> Spring to be done

• AOP - Aspect Oriented Programming

  System-level services to maximize reuse

Sprint architecture

Data Access/Integration

• Spring JDBC lightweight implementation
• ORM - Object Relational Mapping
  • MyBatis
  • Hibernate
• OXM
• ETC.
• Transactions

Web

• WebSocket
• Servlet
• Web
• Splicing components - Portlet

AOP

Core Container

• Beans
• Core
• Context
• Game

Test

Feature

• Non-invasive
  • API Spring Framework will not appear on the business logic

Spring and IoC

• Dependency Injection
• Between Spring's Bean to profile the way organizations together

• pojo - native Java objects
• Bean

[Gymnastics] hello-Spring

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.funtl</groupId>
    <artifactId>hello-spring</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.17.RELEASE</version>
        </dependency>
    </dependencies>
</project>

Example hardcoded

Spring configuration file

• Profiles resources / srping-context.xml - 依赖注入

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="userService" class="com.funtl.hello.spring.service.impl.UserServiceImpl" />
</beans>

• Get the Spring configuration MyTest.java - 控制反转

public class MyTest {
    public static void main(String[] args) {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-context.xml");
        UserService userService = (UserService) applicationContext.getBean("userService");
        userService.sayHi();
    }
}