📅  最后修改于: 2020-11-11 06:58:43             🧑  作者: Mango
构成应用程序主干并由Spring IoC容器管理的对象称为bean 。 Bean是由Spring IoC容器实例化,组装和以其他方式管理的对象。这些bean是使用您提供给容器的配置元数据创建的。例如,以XML
Bean定义包含称为配置元数据的信息,容器知道以下信息时需要使用-
上面所有的配置元数据都转换为组成每个bean定义的一组以下属性。
Sr.No. | Properties & Description |
---|---|
1 |
class This attribute is mandatory and specifies the bean class to be used to create the bean. |
2 |
name This attribute specifies the bean identifier uniquely. In XMLbased configuration metadata, you use the id and/or name attributes to specify the bean identifier(s). |
3 |
scope This attribute specifies the scope of the objects created from a particular bean definition and it will be discussed in bean scopes chapter. |
4 |
constructor-arg This is used to inject the dependencies and will be discussed in subsequent chapters. |
5 |
properties This is used to inject the dependencies and will be discussed in subsequent chapters. |
6 |
autowiring mode This is used to inject the dependencies and will be discussed in subsequent chapters. |
7 |
lazy-initialization mode A lazy-initialized bean tells the IoC container to create a bean instance when it is first requested, rather than at the startup. |
8 |
initialization method A callback to be called just after all necessary properties on the bean have been set by the container. It will be discussed in bean life cycle chapter. |
9 |
destruction method A callback to be used when the container containing the bean is destroyed. It will be discussed in bean life cycle chapter. |
Spring IoC容器与实际写入此配置元数据的格式完全脱钩。以下是向Spring Container提供配置元数据的三种重要方法-
您已经了解了如何将基于XML的配置元数据提供给容器,但是让我们看一下具有不同bean定义的基于XML的配置文件的另一个示例,包括延迟初始化,初始化方法和销毁方法-
您可以查看Spring Hello World示例以了解如何定义,配置和创建Spring Bean。
我们将在单独的章节中讨论基于注释的配置。在开始使用带有注释的Spring Dependency Injection进行编程之前,我们希望在单独的章节中进行讨论,因为我们希望您掌握其他一些重要的Spring概念。