用maven项目运行一个spring 的小样例，注入一个bean

1. pom导入依赖

    <dependencies>
        <!--        spring-context的jar包-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>
        <!--        spring-core的jar包-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>
        <!--        spring-beans的jar包-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>
        <!--        spring-expression的jar包-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>
        <!--        commons.lggging的jar包-->
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>
    </dependencies>

2. 创建接口和实现类

public interface UserDao {
    public  void login();
}

public class UserDaoImpl implements UserDao {
    @Override
    public void login() {
        System.out.println("UserDao login");
    }
}

3. 配置xml文件，放到resources中

<bean id="userDao" class="dao.UserDaoImpl"/>

4. 测试一下

public class test1 {
    public static void main(String[] args) {
        ApplicationContext applicationContext =
                new ClassPathXmlApplicationContext("spring.xml");
        UserDao userDao = (UserDao) applicationContext.getBean("userDao");
        userDao.login();
    }
}

输出：