Spring5 常用注解

1、注解配置

1.1、 applicationContext.xml

配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                           http://www.springframework.org/schema/beans/spring-beans.xsd
                           http://www.springframework.org/schema/context
                           https://www.springframework.org/schema/context/spring-context.xsd">
​
    <!--    扫描包      -->
    <context:component-scan base-package="com.chris"/>
    <!--    开启注解配置 -->
    <context:annotation-config/>
​
​
</beans>

 

1.2 、@Component

注入bean,XML中可以不用再继续配置bean

package com.chris.pojo;
​
import org.springframework.stereotype.Component;
​
@Component
public class UserPOJO {
    public String Name = "UserPOJO";
}

 

1.3 、衍生注解

1.31、@Repository（Dao层）、 @Service（Service层）、 @Controller（层）

package com.chris.dao;
​
import org.springframework.stereotype.Repository;
​
@Repository
public class UserDao {
    public String Name = "UserDao";
}

package com.chris.Services;
​
import org.springframework.stereotype.Service;
​
@Service
public class UserServices {
    public String Name = "UserServices";
}

package com.chris.Controller;
​
import org.springframework.stereotype.Controller;
​
@Controller
public class UserController {
    public String Name = "UserController";
}

 

1.32、注解注入

@Repository
public class UserSetDao {
    @Value("UserSetDao")
    private String Name;
​
    public String getName() {
        return Name;
    }
}

 

1.33、调用方式

 

import com.chris.dao.UserDao;
import com.chris.pojo.UserPOJO;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
​
public class MyTest {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("applictionContext.xml");
        UserPOJO userPOJO = (UserPOJO) context.getBean("userPOJO");
        System.out.println(userPOJO.Name);
​
    }
}