例項化方法

類構造器例項化

package com.yiki.bean.imp;

import com.yiki.service.Service;

/*業務bean*/
public class ServiceBean implements Service {
	@Override
	public void save(){
		System.out.println("serviceBean");
	}

}

<bean id="service" class="com.yiki.bean.imp.ServiceBean"></bean>

靜態工程方法例項化

package com.yiki.bean.imp;

/*工廠方法用來建立bean物件*/
public class ServiceBeanFactory {
	public static ServiceBean creatBean() {
		return new ServiceBean();
	}

}
 

	
	<!-- [2]靜態工廠 -->
	<bean id="serviceFactory" class="com.yiki.bean.imp.ServiceBeanFactory" factory-method="creatBean"></bean>
	

例項工廠方法例項化

這裡沒有static

public  ServiceBean creatBean2() {
		return new ServiceBean();
	}

<!-- [3]例項化工廠 -->
	<bean id="serviceFactory2" class="com.yiki.bean.imp.ServiceBeanFactory" ></bean>
	<bean id="service2" factory-bean="serviceFactory2" factory-method="creatBean2"></bean>
 

測試用例

package com.yiki.Test;

import org.junit.Test;
import org.springframework.beans.factory.serviceloader.ServiceFactoryBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.yiki.service.Service;

public class TestCfg {

	@Test
	public void test1() {
		String xmlPath = "ApplicationContext.xml";
		ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
		
		//通過介面
		Service service = (Service) applicationContext.getBean("service");
		service.save();
	}
	@Test
	public void test2() {
		String xmlPath = "ApplicationContext.xml";
		ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
		
		Service service = (Service) applicationContext.getBean("serviceFactory");
		service.save();
	}
	@Test
	public void test3() {
		String xmlPath = "ApplicationContext.xml";
		ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);
		
		Service service = (Service) applicationContext.getBean("service2");
		service.save();
	}

}
 

bean的作用域

scope="作用域">

singleton

預設，單例

prototype

每次都會返回一個新的物件

bean的生命週期

lazy-init="例項化時機的選擇"

false

不延遲初始化

true

延遲初始化