【Spring源码解析】组件注册-xml注册bean

前言

以前的spring-bean是通过xml注入bean的。

基础环境

1. 创建一个 maven 项目
2. 引入pom依赖

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.3.4</version>
</dependency>

3. 创建一个简单对象

/**
 * @author cuishiying
 * @date 2021-01-22
 */
public class Person {

    private String name;
    private Integer age;

    public Person() {
    }

    public Person(String name, Integer age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

4. 在xml中注册bean

<?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 http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="person" class="cn.idea360.bean.Person">
        <property name="name" value="admin"></property>
        <property name="age" value="17"></property>
    </bean>
</beans>

5. 测试

/**
 * @author cuishiying
 * @date 2021-01-22
 */
public class MainTest {

    public static void main(String[] args) {
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("bean.xml");
        Person bean = (Person) applicationContext.getBean("person");
        System.out.println(bean);  // Person{name='admin', age=17}
    }
}

最后

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