<?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:content="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">
    <!-- 配置一下：bean注解掃描的根路徑（方面后面更簡單存儲對象到spring容器）-->
    <content:component-scan base-package="com.bit"></content:component-scan>
</beans>

2.使用注解將bean對象存儲到spring框架中

注解分類：

1.類注解：@Controller【控制器】，@Service【業(yè)務邏輯層】，@Repository【數(shù)據(jù)持久層】，@Component【組件類】，@Configuration【配置類】

2.方法注解：@Bean（必須配合類注解使用）

@Controller

創(chuàng)建bean對象

package com.bit;

import org.springframework.stereotype.Controller;

/**
 * Description：
 * User: lmp
 * Date: 2022-05-24
 * Time: 19:23
 */
@Controller
public class UserController {
    public void sayHi(String name){
        System.out.println("Hi controller"+name);
    }
}

讀取bean對象

package com.bit;

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

/**
 * Description：
 * User: lmp
 * Date: 2022-05-24
 * Time: 15:25
 */
public class App {
    public static void main(String[] args) {
        //先獲取對象的Spring
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        //從 Spring 中獲得存入的對象(將存入的類首字母小寫，若類名字符大于2個，并且前兩個字符都是大寫，那么使用原類名作為bean的名字)
        UserController userController = context.getBean("userController",UserController.class);
        userController.sayHi("Bit");
    }
}

@Service

和controller一樣

@Repository

和controller一樣

@Configuration

和controller一樣

@Component

和controller一樣

方法注解@Bean

一般寫在組件里面，方法注解必須配合類注解使用，因為Spring默認是類級別的掃描

package com.bit.util;

import com.bit.Model.User;
import com.sun.org.apache.bcel.internal.generic.RETURN;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

/**
 * Description：
 * User: lmp
 * Date: 2022-05-24
 * Time: 21:14
 */
@Component
public class UserBean {
    @Bean //將當前對象存儲在Spring當中
    public User user1(){
        User user = new User();
        user.setId(1);
        user.setName("zhangsan");
        user.setAge(18);
        return user;
    }
}

重命名bean

可以通過設置name屬性給Bean對象進行重命名操作

@Bean重命名可以有多個別名，但是當指定別名之后，方法名就取不到對象了

package com.bit.util;

import com.bit.Model.User;
import com.sun.org.apache.bcel.internal.generic.RETURN;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

/**
 * Description：
 * User: lmp
 * Date: 2022-05-24
 * Time: 21:14
 */
@Component
public class UserBean {
    @Bean(name = {"u1","userInfo1"}) //將當前對象存儲在Spring當中
    public User user1(){
        User user = new User();
        user.setId(1);
        user.setName("zhangsan");
        user.setAge(18);
        return user;
    }

    @Bean(name = "u2") //將當前對象存儲在Spring當中
    public User user2(){
        User user = new User();
        user.setId(1);
        user.setName("lisi");
        user.setAge(18);
        return user;
    }
}