使用单个 spring.xml 文件加载 BeanFactory 和 ApplicationContext 时，Spring 会加载两个不同的实例

Question

我正在编写一些代码来研究从 Spring 容器中获取 bean 的不同方法。为了解决我遇到的问题，我保持代码非常简单。

我已经写了下面的类

三角形类

package org.studyspring.beanfactory;
public class Triangle {
    public String draw() {
        return "Triangle Drawn";
    }
}

Spring.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">
 <bean id ="triangle" class ="org.studyspring.beanfactory.Triangle"/>
</beans>

测试类

package org.studyspring.beanfactory;

import org.junit.BeforeClass;
import org.junit.Test;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.core.io.FileSystemResource;

import static org.junit.Assert.assertEquals;

public class BeanFactoryTest {
private static BeanFactory factory;
private static ApplicationContext context;

    @BeforeClass
    public static void setupBeforeClass(){
        factory = new XmlBeanFactory(new FileSystemResource("./basicSpring/src/test/resources/spring.xml"));
        context= new ClassPathXmlApplicationContext("spring.xml");
    }

    @Test
    public void getTriangleBean_WithBeanFactory(){
        Triangle triangle = (Triangle) factory.getBean("triangle");
        String message = triangle.draw();
        assertEquals("Triangle Drawn",message);
    }

    @Test
    public void getTriangleBean_WithApplicationContext(){
        Triangle triangle = (Triangle) context.getBean("triangle");
        String message = triangle.draw();
        assertEquals("Triangle Drawn",message);
    }

    @Test
    public void triangleBean_ShouldBeSame_WithApplicationContextAndWithBeanFactory(){
        Triangle triangle = (Triangle) factory.getBean("triangle");
        Triangle triangle1 = (Triangle) context.getBean("triangle");
        String message = triangle.draw();
        assertEquals(triangle,triangle1);
    }
}

我认为我的测试用例 triangleBean_ShouldBeSame_WithApplicationContextAndWithBeanFactory 应该已经通过，但实际上它失败了，并出现以下错误

Expected :org.studyspring.beanfactory.Triangle@22c1609b
Actual   :org.studyspring.beanfactory.Triangle@45ad71f0

我问这个问题是因为我有以下假设

1. 当spring容器初始化一个bean时，它的默认作用域是Singleton

2. spring 容器应该只使用一个 bean 实例

3. 此外ApplicationContext 扩展BeanFactory（间接）

4. 我们可以交替使用BeanFactory 和ApplicationContext

我的问题是关于基础的，spring 容器为 beanFactory 和 ApplicationContext 分别加载两个单独的实例是否正确？

Answer 1

这是因为您创建了 2 个不同的容器。您可以制作 2 个 ApplicationContexts

ApplicationContext context1;
ApplicationContext context2;

其中仍然会有两个不同的 Triangle 实例