01-Spring的配置

• 安装Spring

配置pom.xml导入Spring依赖。

<?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">
    <parent>
        <artifactId>Spring</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>01-Spring</artifactId>
<dependencies>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.3.8</version>
    </dependency>

</dependencies>

</project>

• 编写dao层接口

public interface UserDao {
    void getUser();

}

 

• 编写dao层实现

public class UserDaoMysqlImp implements UserDao{

    public void getUser() {
        System.out.println("Mysql的实现");
    }
}

 

• 编写service层

public interface UserService {
    void getUser();
}

 

• 编写service层实现

public class UserServiceImp implements UserService{

    private UserDao userDao;

    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }

    public void getUser() {
        userDao.getUser();
    }
}

• 配置ApplicationContext.xml

通过<bean>标签将dao和service的实现类注入Spring容器，通过<property>标签将dao层类的对象通过set的方式注入到service层类的属性中。

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd">
   <!--alias的name是原名字，alias是起的别名-->
    <bean id="mysql" class="com.java.dao.UserDaoMysqlImp"></bean>

    <bean id="UserService" class="com.java.service.UserServiceImp">
       <property name="userDao"  ref="mysql"></property>
    </bean>

    <alias name="UserService" alias="asd"></alias>
</beans>

• 编写测试

public class MyTest {
    @Test
    public void test01(){

        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        UserFactory getUser = context.getBean("getUser", UserFactory.class);
        System.out.println(getUser.getUser());
    }
}