spring boot和spring cloud项目中配置文件application和bootstrap中的值与对应的配置类绑定处理

在前面的文章基础上

https://blog.csdn.net/zlpzlpzyd/article/details/136065211

加载完文件转换为 Environment 中对应的值之后，接下来需要将对应的值与对应的配置类进行绑定，方便对应的组件取值处理接下来的操作。

对应的配置值与配置类绑定通过 ConfigurationPropertiesBindingPostProcessor 来处理。

首先调用 ApplicationContextAware#setApplicationContext() 将 ApplicationContext 对象向当前类赋值。

然后利用上面的 ApplicationContext 调用 InitializingBean#afterPropertiesSet() 进行 BeanDefinitionRegistry 和 ConfigurationPropertiesBinder 获取。

最后调用 BeanPostProcessor#postProcessBeforeInitialization() 进行前置处理，调用 ConfigurationPropertiesBinder 中的方法处理后面的绑定值逻辑。

获取 Binder 对象进行绑值处理

通过 findProperty() 找到对应的属性，对应值不为空返回

调用 SpringConfigurationPropertySources 的迭代器将 Environment 中的值复制到变量 cache 中。

遍历时生成 SpringConfigurationPropertySources$SourcesIterator，将 sources 中的值传递到 SourcesIterator 的 iterators 变量中。

首次迭代为 environmentProperties，对应接口 ConfigurableEnvironment 的实现类 StandardServletEnvironment。

遍历变量 sources 中的元素 environmentProperties 的迭代器中的数据

0 = {ConfigurationPropertySourcesPropertySource@4977} "ConfigurationPropertySourcesPropertySource {name='configurationProperties'}"
1 = {PropertySource$StubPropertySource@4978} "StubPropertySource {name='servletConfigInitParams'}"
2 = {PropertySource$StubPropertySource@4979} "StubPropertySource {name='servletContextInitParams'}"
3 = {PropertiesPropertySource@4886} "PropertiesPropertySource {name='systemProperties'}"
4 = {SystemEnvironmentPropertySourceEnvironmentPostProcessor$OriginAwareSystemEnvironmentPropertySource@4882} "OriginAwareSystemEnvironmentPropertySource {name='systemEnvironment'}"
5 = {RandomValuePropertySource@4880} "RandomValuePropertySource {name='random'}"
6 = {MapPropertySource@4892} "MapPropertySource {name='springCloudClientHostInfo'}"
7 = {OriginTrackedMapPropertySource@4890} "OriginTrackedMapPropertySource {name='applicationConfig: [classpath:/application.yml]'}"
8 = {OriginTrackedMapPropertySource@4888} "OriginTrackedMapPropertySource {name='applicationConfig: [classpath:/bootstrap.yml]'}"
9 = {MapPropertySource@4894} "MapPropertySource {name='springCloudDefaultProperties'}"
10 = {CachedRandomPropertySource@4896} "CachedRandomPropertySource {name='cachedrandom'}"

cache 中的数据

{RandomValuePropertySource@4994} "RandomValuePropertySource {name='random'}" -> {SpringConfigurationPropertySource@4995} "RandomValuePropertySource {name='random'}"
{SystemEnvironmentPropertySourceEnvironmentPostProcessor$OriginAwareSystemEnvironmentPropertySource@4996} "OriginAwareSystemEnvironmentPropertySource {name='systemEnvironment'}" -> {SpringIterableConfigurationPropertySource@4997} "OriginAwareSystemEnvironmentPropertySource {name='systemEnvironment'}"
{PropertiesPropertySource@4998} "PropertiesPropertySource {name='localProperties'}" -> {SpringIterableConfigurationPropertySource@4999} "PropertiesPropertySource {name='localProperties'}"
{PropertiesPropertySource@5000} "PropertiesPropertySource {name='systemProperties'}" -> {SpringIterableConfigurationPropertySource@5001} "PropertiesPropertySource {name='systemProperties'}"
{OriginTrackedMapPropertySource@5002} "OriginTrackedMapPropertySource {name='applicationConfig: [classpath:/bootstrap.yml]'}" -> {SpringIterableConfigurationPropertySource@5003} "OriginTrackedMapPropertySource {name='applicationConfig: [classpath:/bootstrap.yml]'}"
{OriginTrackedMapPropertySource@5004} "OriginTrackedMapPropertySource {name='applicationConfig: [classpath:/application.yml]'}" -> {SpringIterableConfigurationPropertySource@5005} "OriginTrackedMapPropertySource {name='applicationConfig: [classpath:/application.yml]'}"
{MapPropertySource@5006} "MapPropertySource {name='springCloudClientHostInfo'}" -> {SpringIterableConfigurationPropertySource@5007} "MapPropertySource {name='springCloudClientHostInfo'}"
{MapPropertySource@5008} "MapPropertySource {name='springCloudDefaultProperties'}" -> {SpringIterableConfigurationPropertySource@5009} "MapPropertySource {name='springCloudDefaultProperties'}"
{CachedRandomPropertySource@5010} "CachedRandomPropertySource {name='cachedrandom'}" -> {SpringConfigurationPropertySource@5011} "CachedRandomPropertySource {name='cachedrandom'}"

以迭代器中的值顺序为准与 cache 中进行比对，返回对应的配置类，然后再将对应的配置属性从对应的配置文件中获取。

可以发现，对应配置值顺序如下