Spring 使用注解创建对象

今天药忘吃喽~ 2022-12-17 11:55 185阅读 0赞

引入AOP依赖（spring-aop-5.2.6.RELEASE.jar）

![20201023161245702.png][]

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# 一、创建类 #

在类上面添加创建对象的注解 @Component(value = "user")

User.java

/*
        注解里面value属性值可以不写
        默认是类名称,首字母小写
    */
    @Component(value = "user")  //等于<bean id="userService" class="**.L_注解开发.a_对象创建">
    public class User {
        public void add(){
            System.out.println("add方法......");
        }
    }

## ##

# 二、编写配置文件 #

开启组件扫描：<context:component-scan base-package="要扫描的包路径"></context:component-scan>

bean21.xml

<?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 http://www.springframework.org/schema/context/spring-context.xsd">
    
        
        <context:component-scan base-package="com.health.IOC.L_注解开发.a_对象创建"></context:component-scan>
    </beans>

## ##

# 三、测试 #

TestLa.java

public class TestLa {
        public static void main(String[] args) {
            ApplicationContext context =
                    new ClassPathXmlApplicationContext("com/health/IOC/L_注解开发/a_对象创建/bean21.xml");
            User user = context.getBean("user", User.class);
            System.out.println(user);
            user.add();
        }
    }

输出结果：

![20201023160317164.png][]

[20201023161245702.png]: /images/20221122/1ec33ff0040b47eea72ead2710a19b15.png
[20201023160317164.png]: /images/20221122/cb341218ef774f168d4d568a0b0dabee.png