spring bean作用域

Posted 2020-09-14 jzssuanfa

概要：

实例代码具体解释：

文件夹结构

Car.java

package com.coslay.beans.autowire;

public class Car {
	private String brand;
	private double price;

	public String getBrand() {
		return brand;
	}

	public void setBrand(String brand) {
		this.brand = brand;
	}

	public double getPrice() {
		return price;
	}

	public void setPrice(double price) {
		this.price = price;
	}

	@Override
	public String toString() {
		return "Car [brand=" + brand + ", price=" + price + "]";
	}
	
	public Car(){
		System.out.println("Car‘s Constructor...");
	}

}

Main.java

package com.coslay.beans.scope;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.coslay.beans.autowire.Car;

public class Main {
	public static void main(String[] args) {
		ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-scope.xml");
		
		Car car = (Car) ctx.getBean("car");
		Car car2 = (Car) ctx.getBean("car");
		
		System.out.println(car == car2);
	}
}

beans-scope.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">

	<!-- 
		使用bean的scope属性来配置bean的作用域
		singleton:默认值。容器初始化时创建bean实例，在整个容器的生命周期内仅仅创建这一个bean。单例的。
		prototype:原型的。
容器初始化时不创建bean的实例。
而在每次请求时都创建一个新的Bean实例。并返回。
		
	-->
	<bean id="car" class="com.coslay.beans.autowire.Car"
		scope="prototype">
		<property name="brand" value="Audi"></property>
		<property name="price" value="300000000"></property>
	</bean>

</beans>