Hello Spring

Hello Spring

1.首先完成hello类的创

public class Hello {
    private String str;

    public String getStr() {
        return str;
    }

    public void setStr(String str) {
        this.str = str;
    }

    @Override
    public String toString() {
        return "hello"+"{"+"str="+str+'\''+"}";
    }
    
    

2.完成xml文件

<?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">

<!--使用spring创建框架创建对象，在spring中这些都称为bean
类型 变量名= new类型（）；
id=变量名
calls=new类型（）；
property：给对象中的属性设置一个值
-->
	<bean id="hello" class="com.wjj.pojo.Hello">
		<property name="str" value="spring">
		</property>
	</bean>


</beans>

3.在测试方法中调用

public class MyTest {
    @Test
    public void test(){
        //获取spring的上下文对象，即在beans.xml中的对象全实例化了
        ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        //对象都在spring的管理，
        Hello hello= (Hello) context.getBean("hello");
        //System.out.println(context.getBean(Hello.class));
        System.out.println(hello.toString());
    }
}

4.练习

​ 1.完成UserDao的创建

ackage com.wjj.dao;

public interface UserDao {
    void getUserDao();

}

​ 2.UserDaoImpl与UserDaomysqlImpl的创建

public class UserDaoImpl implements UserDao {

    @Override
    public void getUserDao() {
        System.out.println("UserDaoImpl");
    }
}

public class UserDaoMysqlImpl  implements UserDao {
    public void getUserDao() {
        System.out.println("UserDaoMysqlImpl");
    }
}

​ 3.完成Service接口和实现

public interface UserService {
    void getUser();
}

public class UserServiceImpl implements UserService {
    UserDao userDao;
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    @Override
    public void getUser() {
        userDao.getUserDao();
    }
}

​ 4.完成xml文件

<?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">
    <bean id="mysql" class="com.wjj.dao.UserDaoMysqlImpl">
    </bean>
    <bean id="userDaoImpl" class="com.wjj.dao.UserDaoImpl">
    </bean>
    <bean id="service" class="com.wjj.Service.UserServiceImpl">
<!--
fer：引用spring容器中创建好的对象
value：具体的值，基本的数据类型
-->
        <property name="userDao" ref="userDaoImpl">

        </property>
    </bean>
</beans>

	5.测试以及结果

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class UserServiceImplTest{

    @Test
    public void getUserDao() {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");
        UserServiceImpl service=(UserServiceImpl) applicationContext.getBean("service");
        service.getUser();

    }
}