Spring's IOC annotation configuration

Spring's IOC annotation configuration

step

1. Import one more package in the most basic Spring environment

   • spring-aop-4.3.8.RELEASE.jar

2. Import another constraint , the import method is the same as before

   • ..\spring-framework-4.3.8.RELEASE-dist\spring-framework-4.3.8.RELEASE\schema\contextImport spring-context-4.3.xsd under the path
   • Note : When importing a Schema constraint, there can only be one empty namespace in the constraint

3. Enable *spring support for annotations* in the applicationContext.xml configuration file

   <!-- 开启spring对注解的ioc支持,对包进行组件扫描 -->
   <context:component-scan base-package="com"></context:component-scan>
   

code

• Write annotations in objects

@Component("User")
public class User {
    private String name;
    private int age;
    private Car car;
    private Date birthday;

    set/get()....
}

• applicaionContext.xml configuration file

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans" 
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd ">

    <!-- 开启spring对注解的ioc支持,对包进行组件扫描 -->
    <context:component-scan base-package="com"></context:component-scan>
</beans>

• test class

/**
 * 测试注解配置能否拿到对象
 */
@Test
public void getUser(){
    //获取工厂类
    ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

    //获取对象
    User user = (User) context.getBean("User");
    System.out.println(user);
}