spring配置（bean的scope属性）

野性酷女 2022-04-23 06:18 285阅读 0赞

> scope属性

1.singleton(默认值)：单例对象.被标识为单例的对象在spring容器中只会存在一个实例。

2.prototype:多例原型.被标识为多例的对象,每次再获得才会创建.每次创建都是新的对象.整合struts2时,ActionBean必须配置为多例的。因为每个请求访问Action都会创建一个Action对象

applicationContext.xml:

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd ">
    
    	<bean name="user" class="cn.itcast.bean.User" scope="singleton"></bean>
    	
    </beans>

User.java

public class User {
    	private String name;
    	private Integer age;
    	
    	public User() {
    		System.out.println("user构造");
    	}
    
    	public String getName() {
    		return name;
    	}
    
    	public void setName(String name) {
    		this.name = name;
    	}
    
    	public Integer getAge() {
    		return age;
    	}
    
    	public void setAge(Integer age) {
    		this.age = age;
    	}
    	
    	
    }

Demo.java

@Test
    	public void func() {
    		ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
    		User user1 = (User) ac.getBean("user");
    		User user2 = (User) ac.getBean("user");
    		User user3 = (User) ac.getBean("user");
    		System.out.println(user1==user3);
    	}

效果：（控制台）

![20190124154014200.png][]

将scope改为prototype

效果：（控制台）

![20190124154200256.png][]

[20190124154014200.png]: /images/20220323/9d95d934eb0c4b308c5cae58d47b47e5.png
[20190124154200256.png]: /images/20220323/161165d4d9d249f2b2b6195d63b9bbd7.png