java - 为什么 Spring 中的作用域会影响 Spring 中类的加载

Question

类(class)学生 取决于类(class)结果

<bean id = "result" lazy-init = "false">
</bean>
<bean id = "student" lazy-init = "true">
</bean>

Result: result bean 将在容器启动时加载，student 将在我们调用 getBean 方法时加载。

<bean id = "result" lazy-init = "false" scope = "prototype">
</bean>
<bean id = "student" lazy-init = "true" scope = "Singleton">
</bean>

结果:容器启动时不会加载任何 bean。

问题:为什么作用域会影响类加载？范围与类加载时间有什么关系？

Answer 1

根据 documentation

The non-singleton, prototype scope of bean deployment results in the creation of a new bean instance every time a request for that specific bean is made. That is, the bean is injected into another bean or you request it through a getBean() method call on the container. As a rule, use the prototype scope for all stateful beans and the singleton scope for stateless beans.

由于您尚未调用 getBean 或将其注入(inject)到另一个 bean，因此尚未创建此 bean。

顺便说一下，即使您将 singletone bean 声明为 lazy-init="true"，如果您要注入(inject)它(对于带有 @Autowired 注释的示例)到其他非惰性 bean。