实例化，执行，初始化，销毁bean对象

来源：互联网发布：安卓变声软件编辑：程序博客网时间：2024/06/08 07:10

1.修改applicationContext.xml，通过设置配置文件属性lazy-init="true"，可以改变Spring容器创建对象的时机。
2.在顶级的<beans/>元素中的default-lazy-init属性，可以为容器所有<bean>指定延迟实例化特性

3.从输出结果可以看出，当使用ExampleBean对象时，才被创建，即，设置lazy-init="true"属性后，对象不使用不创建。

package org.spring.dao;public class ExampleBean {public ExampleBean() {System.out.println("实例化ExampleBean");}public void execute() {System.out.println("执行ExampleBean处理");}public void init() {System.out.println("初始化ExampleBean对象");}public void destroy() {System.out.println("销毁ExampleBean对象");}}

package org.spring.dao;public class ExampleBean1 {public ExampleBean1() {System.out.println("实例化ExampleBean1");}}

<?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"xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee"xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jpa="http://www.springframework.org/schema/data/jpa"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsdhttp://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsdhttp://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsdhttp://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd"default-lazy-init="true" default-init-method="init"default-destroy-method="destroy"><bean id="exampleBean" class="org.spring.dao.ExampleBean" scope="singleton"init-method="init" destroy-method="destroy" depends-on="bean1" /><bean id="bean1" class="org.spring.dao.ExampleBean1" lazy-init="true" /></beans>

package org.spring.test;import org.junit.Test;import org.spring.dao.ExampleBean;import org.springframework.context.ApplicationContext;import org.springframework.context.support.AbstractApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class testCase {@Testpublic void testExampleBean() {// 实例化Spring容器示例String conf = "applicationContext.xml";ApplicationContext ac = new ClassPathXmlApplicationContext(conf);//System.out.println(ac);// 获取ExampleBean对象ExampleBean bean1 = ac.getBean("exampleBean", ExampleBean.class);ExampleBean bean2 = ac.getBean("exampleBean", ExampleBean.class);System.out.println(bean1 == bean2);// 关闭Spring容器, 注意AbstractApplicationContext类型定义了 close()方法AbstractApplicationContext ctx = (AbstractApplicationContext) ac;ctx.close();}}

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