java_spring_实例化bean的3种方法

//Dao类

package com.dao.bean.www;

public interface PersonServiceDao {

	public abstract void save();

}

//Bean

package com.bean.www;

import com.dao.bean.www.PersonServiceDao;

public class PersonServiceBean implements PersonServiceDao {

	@Override
	public void save() {
		System.out.println("method save()");
	}
}

//第二第三种需要的工厂方法

package com.factory.www;

import com.bean.www.PersonServiceBean;

public class PersonServiceFactory {
	public static PersonServiceBean creatBean() {
		return new PersonServiceBean();
	}
	
	public PersonServiceBean creatBean2() {
		return new PersonServiceBean();
	}
	
}

//配置文件

<?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:p="http://www.springframework.org/schema/p"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
	
	<!-- 获取bean -->
	<bean id="personService" class="com.bean.www.PersonServiceBean"></bean>

	<!-- 静态工厂方法 -->	
	<bean id="beanFactory1" class="com.factory.www.PersonServiceFactory" factory-method="creatBean" ></bean>
	
	
	<!-- 非静态工厂方法  1.首先实例化工厂类bean -->
	<bean id="beanFactory2" class="com.factory.www.PersonServiceFactory" ></bean>
	<bean id="GetBean" factory-bean="beanFactory2" factory-method="creatBean2" ></bean>
</beans>

//测试类

package com.itcast.www;

import static org.junit.Assert.*;

import org.junit.BeforeClass;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.dao.bean.www.PersonServiceDao;

public class TestCaseDemo {

	@BeforeClass
	public static void setUpBeforeClass() throws Exception {
	}

	@Test
	public void instanceSpring() {

		ApplicationContext ctx = new ClassPathXmlApplicationContext(
				"applicationContext.xml");

//		PersonServiceDao personService = (PersonServiceDao) ctx
//				.getBean("personService");
//		PersonServiceDao personService = (PersonServiceDao) ctx
//				.getBean("beanFactory1");
		PersonServiceDao personService = (PersonServiceDao) ctx
				.getBean("GetBean");
		personService.save();

	}

}

//************************初始化和构造函数******************************

package com.bean.www;

import com.dao.bean.www.PersonServiceDao;
/*
 * 初始化方法执行在构造方法之后
 * 需要在配置文件中配置初始化或者销毁方法
 * 用于打开或者关闭资源等
 * 单实例-lazy-init=true 获取容器后创建
 * lazy-init=false ctx.getbean实现
 * 直到关闭才执行destroy方法
 * 关闭方法 ctx.close();
 * */
public class PersonServiceBean implements PersonServiceDao {

	public void init(){
		System.out.println("init..................");
	}
	
	@Override
	public void save() {
		System.out.println("method save()");
	}
	
	public void destroy(){
		System.out.println("destroy..................");
	}
}

//配置文件

<bean id="personService" class="com.bean.www.PersonServiceBean" lazy-init="false" init-method="init" destroy-method=""></bean>