bean生命周期

生命周期

• bean对象创建（调用无参构造器）
• 给bean对象设置属性
• bean的后置处理器（初始化之前）
• bean对象初始化（需在配置bean时指定初始化方法）
• bean的后置处理器（初始化之后）
• bean对象就绪可以使用
• bean对象销毁（需在配置bean时指定销毁方法）
• IOC容器关闭

通过代码验证

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.atguigu.spring6</groupId>
        <artifactId>spring6</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>spring6-ioc-xml</artifactId>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <dependencies>
        <!--spring context依赖-->
        <!--当你引入Spring Context依赖之后，表示将Spring的基础依赖引入了-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>6.0.3</version>
        </dependency>

        <!--junit5测试-->
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.3.1</version>
        </dependency>

        <!--log4j2的依赖-->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.19.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-slf4j2-impl</artifactId>
            <version>2.19.0</version>
        </dependency>
    </dependencies>
</project>

bean-lift.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="user" class="com.atguigu.spring6.life.User" destroy-method="destroyMethod" init-method="initMethod">
        <property name="uname" value="zs"/>
    </bean>

    <bean id="myBeanProcessor" class="com.atguigu.spring6.life.MyBeanProcessor" ></bean>
</beans>

User MyBeanProcessor

package com.atguigu.spring6.life;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * 时间：2024/7/24
 * 作者：jinyu
 * 描述：
 */

public class User {
    private String uname;

    public User() {
        System.out.println("bean对象创建（调用无参构造器）");
    }

    public User(String uname) {
        this.uname = uname;
    }

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        System.out.println("给bean对象设置属性");
        this.uname = uname;
    }

    private void destroyMethod() {
        System.out.println("bean对象销毁（需在配置bean时指定销毁方法）");
    }

    private void initMethod() {
        System.out.println("bean对象初始化（需在配置bean时指定初始化方法）");
    }

    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("bean-lift.xml");
        User user = context.getBean(User.class);
        System.out.println("bean对象就绪可以使用："+user);
        context.close();
    }
}

package com.atguigu.spring6.life;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;

/**

• 时间：2024/7/24
• 作者：jinyu
• 描述：
  */

public class MyBeanProcessor implements BeanPostProcessor {
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {

    System.out.println("bean的后置处理器（初始化之前）");
    return bean;
}

@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
    System.out.println("bean的后置处理器（初始化之后）");
    return bean;
}

}

执行User.main

验证整个生命周期，参考可以直接复制代码运行。