spring对象的获取及属性赋值方式（二）

11、bean对象的初始化和销毁方法

​ 在创建对象的时候，我们可以根据需要调用初始化和销毁的方法

Address.java

package com.mashibing.bean;


public class Address {
    private String province;
    private String city;
    private String town;

    public Address() {
        System.out.println("address");
    }

    public Address(String province, String city, String town) {
        this.province = province;
        this.city = city;
        this.town = town;
    }
    
    public void init(){
        System.out.println("对象被初始化");
    }
    
    public void destory(){
        System.out.println("对象被销毁");
    }

    public String getProvince() {
        return province;
    }

    public void setProvince(String province) {
        this.province = province;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getTown() {
        return town;
    }

    public void setTown(String town) {
        this.town = town;
    }

    @Override
    public String toString() {
        return "Address{" +
                "province='" + province + '\'' +
                ", city='" + city + '\'' +
                ", town='" + town + '\'' +
                '}';
    }
}
ioc.xml

<!--bean生命周期表示bean的创建到销毁
    如果bean是单例，容器在启动的时候会创建好，关闭的时候会销毁创建的bean
    如果bean是多例，获取的时候创建对象，销毁的时候不会有任何的调用
-->
<bean id="address" class="com.mashibing.bean.Address" init-method="init" destroy-method="destory" scope="prototype"></bean>
SpringDemoTest.java

import com.mashibing.bean.Address;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringDemoTest {
    public static void main(String[] args) {
        ApplicationContext context=new ClassPathXmlApplicationContext("ioc1.xml");
        Address address = context.getBean("address", Address.class);
        System.out.println(address);
        //applicationContext没有close方法，需要使用具体的子类
        ((ClassPathXmlApplicationContext)context).close();
    }
}  

12、配置bean对象初始化方法的前后处理方法

spring中包含一个BeanPostProcessor的接口，可以在bean的初始化方法的前后调用该方法，如果配置了初始化方法的前置和后置处理器，无论是否包含初始化方法，都会进行调用

ioc.xml

<bean id="myBeanPostProcessor" class="com.mashibing.bean.MyBeanPostProcessor"></bean>