Spring第一篇【快速入门】

快速入门步骤：

1. 导入坐标

<?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>org.example</groupId>
    <artifactId>spring-day01</artifactId>
    <version>1.0-SNAPSHOT</version>

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.0.5.RELEASE</version>
    </dependency>
</dependencies>
</project>

2. 创建bean

3. 创建并配置applicationContext.xml

<?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="userDao" class="com.example.demo.dao.UserDao"/>

</beans>

4. 加载applicationContext.xml

加载applicationContext.xml的两种方式

ApplicationContext ac = new ClasspathXmlApplicationContext("applicationContext.xml");

ApplicationContext ac = new FileSystemXmlApplicationContext("F:\\my:\\applicationContext.xml");

5. 获取bean实例

UserDao ud = (UserDao)ac.getBean("userDao")