这篇文章主要介绍“dubbo中DubboApplicationContextInitializer的具体用法”，在日常操作中，相信很多人在dubbo中DubboApplicationContextInitializer的具体用法问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”dubbo中DubboApplicationContextInitializer的具体用法”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
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dubbo-spring-boot-project-2.7.3/dubbo-spring-boot-compatible/autoconfigure/src/main/java/org/apache/dubbo/spring/boot/context/DubboApplicationContextInitializer.java
public class DubboApplicationContextInitializer implements ApplicationContextInitializer, Ordered {
@Override
public void initialize(ConfigurableApplicationContext applicationContext) {
overrideBeanDefinitions(applicationContext);
}
private void overrideBeanDefinitions(ConfigurableApplicationContext applicationContext) {
applicationContext.addBeanFactoryPostProcessor(new OverrideBeanDefinitionRegistryPostProcessor());
applicationContext.addBeanFactoryPostProcessor(new DubboConfigBeanDefinitionConflictProcessor());
}
@Override
public int getOrder() {
return HIGHEST_PRECEDENCE;
}
}DubboApplicationContextInitializer实现了ApplicationContextInitializer, Ordered接口，initialize方法执行overrideBeanDefinitions，它往applicationContext添加了OverrideBeanDefinitionRegistryPostProcessor、DubboConfigBeanDefinitionConflictProcessor；getOrder返回的是HIGHEST_PRECEDENCE
dubbo-spring-boot-project-2.7.3/dubbo-spring-boot-compatible/autoconfigure/src/main/java/org/apache/dubbo/spring/boot/beans/factory/config/OverrideBeanDefinitionRegistryPostProcessor.java
public class OverrideBeanDefinitionRegistryPostProcessor implements BeanDefinitionRegistryPostProcessor {
@Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
registerInfrastructureBean(registry, BEAN_NAME, DubboConfigBeanCustomizer.class);
}
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
}
}OverrideBeanDefinitionRegistryPostProcessor实现了BeanDefinitionRegistryPostProcessor接口，其postProcessBeanDefinitionRegistry方法调用了BeanRegistrar.registerInfrastructureBean方法注册DubboConfigBeanCustomizer
dubbo-2.7.3-sources.jar!/org/apache/dubbo/config/spring/util/BeanRegistrar.java
public class BeanRegistrar {
/**
* Register Infrastructure Bean
*
* @param beanDefinitionRegistry {@link BeanDefinitionRegistry}
* @param beanType the type of bean
* @param beanName the name of bean
*/
public static void registerInfrastructureBean(BeanDefinitionRegistry beanDefinitionRegistry,
String beanName,
Class beanType) {
if (!beanDefinitionRegistry.containsBeanDefinition(beanName)) {
RootBeanDefinition beanDefinition = new RootBeanDefinition(beanType);
beanDefinition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
beanDefinitionRegistry.registerBeanDefinition(beanName, beanDefinition);
}
}
}registerInfrastructureBean在beanDefinitionRegistry没有该beanDefinition的情况下会注册BeanDefinition.ROLE_INFRASTRUCTURE的bean
dubbo-spring-boot-project-2.7.3/dubbo-spring-boot-compatible/autoconfigure/src/main/java/org/apache/dubbo/spring/boot/beans/factory/config/DubboConfigBeanCustomizer.java
@Deprecated
class DubboConfigBeanCustomizer extends NamePropertyDefaultValueDubboConfigBeanCustomizer {
@Override
public void customize(String beanName, AbstractConfig dubboConfigBean) {
boolean valid = isValidPropertyName(dubboConfigBean, beanName);
if (valid) {
super.customize(beanName, dubboConfigBean);
}
}
private boolean isValidPropertyName(AbstractConfig dubboConfigBean, String propertyValue) {
boolean valid = true;
String propertyName = "name";
// AbstractConfig.checkName(String,String)
Method method = findMethod(AbstractConfig.class, "checkName", String.class, String.class);
try {
if (!method.isAccessible()) {
method.setAccessible(true);
}
if (BeanUtils.getPropertyDescriptor(dubboConfigBean.getClass(), propertyName) != null) {
invokeMethod(method, null, propertyName, propertyValue);
}
} catch (IllegalStateException e) {
valid = false;
}
return valid;
}
}DubboConfigBeanCustomizer继承了NamePropertyDefaultValueDubboConfigBeanCustomizer，其customize方法会先校验propertyName，在valid的情况下才会执行父类的customize方法
dubbo-spring-boot-project-2.7.3/dubbo-spring-boot-compatible/autoconfigure/src/main/java/org/apache/dubbo/spring/boot/beans/factory/config/DubboConfigBeanDefinitionConflictProcessor.java
public class DubboConfigBeanDefinitionConflictProcessor implements BeanDefinitionRegistryPostProcessor, Ordered {
private final Logger logger = LoggerFactory.getLogger(getClass());
private BeanDefinitionRegistry registry;
private Environment environment;
@Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
this.registry = registry;
}
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
resolveUniqueApplicationConfigBean(registry, beanFactory);
}
/**
* Resolve the unique {@link ApplicationConfig} Bean
*
* @param registry {@link BeanDefinitionRegistry} instance
* @param beanFactory {@link ConfigurableListableBeanFactory} instance
* @see EnableDubboConfig
*/
private void resolveUniqueApplicationConfigBean(BeanDefinitionRegistry registry,
ConfigurableListableBeanFactory beanFactory) {
this.environment = beanFactory.getBean(ENVIRONMENT_BEAN_NAME, Environment.class);
String[] beansNames = beanNamesForTypeIncludingAncestors(beanFactory, ApplicationConfig.class);
if (beansNames.length < 2) { // If the number of ApplicationConfig beans is less than two, return immediately.
return;
}
// Remove ApplicationConfig Beans that are configured by "dubbo.application.*"
Stream.of(beansNames)
.filter(this::isConfiguredApplicationConfigBeanName)
.forEach(registry::removeBeanDefinition);
beansNames = beanNamesForTypeIncludingAncestors(beanFactory, ApplicationConfig.class);
if (beansNames.length > 1) {
throw new IllegalStateException(String.format("There are more than one instances of %s, whose bean definitions : %s",
ApplicationConfig.class.getSimpleName(),
Stream.of(beansNames)
.map(registry::getBeanDefinition)
.collect(Collectors.toList()))
);
}
}
private boolean isConfiguredApplicationConfigBeanName(String beanName) {
boolean removed = BeanFactoryUtils.isGeneratedBeanName(beanName)
// Dubbo ApplicationConfig id as bean name
|| Objects.equals(beanName, environment.getProperty("dubbo.application.id"));
if (removed) {
if (logger.isWarnEnabled()) {
logger.warn("The {} bean [ name : {} ] has been removed!", ApplicationConfig.class.getSimpleName(), beanName);
}
}
return removed;
}
@Override
public int getOrder() {
return LOWEST_PRECEDENCE;
}
}DubboConfigBeanDefinitionConflictProcessor实现了BeanDefinitionRegistryPostProcessor, Ordered接口；postProcessBeanFactory方法会执行resolveUniqueApplicationConfigBean，校验同一个beanDefinition是否会有多个实例，有的话会抛出IllegalStateException；getOrder返回的是LOWEST_PRECEDENCE
DubboApplicationContextInitializer实现了ApplicationContextInitializer, Ordered接口，initialize方法执行overrideBeanDefinitions，它往applicationContext添加了OverrideBeanDefinitionRegistryPostProcessor、DubboConfigBeanDefinitionConflictProcessor；getOrder返回的是HIGHEST_PRECEDENCE
到此，关于“dubbo中DubboApplicationContextInitializer的具体用法”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注创新互联网站，小编会继续努力为大家带来更多实用的文章！
