Spring--Spring入门

<dependencies>
  <dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.11</version>
    <scope>test</scope>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>4.3.7.RELEASE</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>4.3.7.RELEASE</version>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-beans</artifactId>
      <version>4.3.7.RELEASE</version>
  </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-expression</artifactId>
      <version>4.3.7.RELEASE</version>
    </dependency>
  <dependency>
    <groupId>commons-logging</groupId>
    <artifactId>commons-logging</artifactId>
    <version>1.2</version>
  </dependency>
  <dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
  </dependency>
</dependencies>

public interface UserService {

    public void sayHello();
}

public class UserServiceImpl implements  UserService{
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    //添加属性
    private String name;
    @Override
    public void sayHello() {
        System.out.print("hello spring" + name);
    }
}

public class SpringDemo1 {
    @Test
    /**
     * 传统方式开发
     */
    public void demo1(){
        //UserService userService = new UserServiceImpl();
        UserServiceImpl userService = new UserServiceImpl();
        //设置属性 传统方法要改代码 就不好了
        userService.setName("张三");
        userService.sayHello();
    }

    @Test
    /**
     * 使用Spring 的方式
     */
    public void demo2(){
        //创建Spring的工厂
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        //通过工厂获得类
        UserService userService = (UserService) applicationContext.getBean("userService");

        userService.sayHello();
    }
}

<?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">

    <!-- UserService的创建权交给了Spring-->
    <bean id="userService" class="com.windbag.ioc.demo1.UserServiceImpl">

        <!-- 设置属性-->
        <property name="name" value="李四"></property>
    </bean>

</beans>