doc: Spring-BeanDefinitionReaderUtils.md

README.md

@@ -75,6 +75,7 @@
 
 * [Spring MultiValueMap](/docs/Spring/clazz/Spring-MultiValueMap.md)
 * [Spring MethodOverride](/docs/Spring/clazz/Spring-MethodOverride.md)
+* [Spring BeanDefinitionReaderUtils](/docs/Spring/clazz/Spring-BeanDefinitionReaderUtils.md)
 
 
 ### Spring5 新特性

docs/Spring/clazz/Spring-BeanDefinitionReaderUtils.md

@@ -0,0 +1,145 @@
+# Spring BeanDefinitionReaderUtils
+- Author: [HuiFer](https://github.com/huifer)
+- 源码阅读仓库: [SourceHot-spring](https://github.com/SourceHot/spring-framework-read)
+
+
+
+## createBeanDefinition
+- `org.springframework.beans.factory.support.BeanDefinitionReaderUtils.createBeanDefinition`
+
+
+
+```java
+public static AbstractBeanDefinition createBeanDefinition(
+      @Nullable String parentName, @Nullable String className, @Nullable ClassLoader classLoader) throws ClassNotFoundException {
+
+   GenericBeanDefinition bd = new GenericBeanDefinition();
+   // 设置 父bean
+   bd.setParentName(parentName);
+   if (className != null) {
+      if (classLoader != null) {
+         // 设置 class
+         // 内部是通过反射创建 class
+         bd.setBeanClass(ClassUtils.forName(className, classLoader));
+      }
+      else {
+         // 设置 class name
+         bd.setBeanClassName(className);
+      }
+   }
+   return bd;
+}
+```
+
+
+
+## generateBeanName
+
+- `org.springframework.beans.factory.support.BeanDefinitionReaderUtils.generateBeanName(org.springframework.beans.factory.config.BeanDefinition, org.springframework.beans.factory.support.BeanDefinitionRegistry, boolean)`
+
+```java
+	public static String generateBeanName(
+			BeanDefinition definition, BeanDefinitionRegistry registry, boolean isInnerBean)
+			throws BeanDefinitionStoreException {
+
+		// 获取 bean class 的名称
+		// Class.getName()
+		String generatedBeanName = definition.getBeanClassName();
+		if (generatedBeanName == null) {
+			// 父类名称是否存在
+			if (definition.getParentName() != null) {
+				generatedBeanName = definition.getParentName() + "$child";
+			}
+			// 工厂 beanName 是否为空
+			else if (definition.getFactoryBeanName() != null) {
+				generatedBeanName = definition.getFactoryBeanName() + "$created";
+			}
+		}
+		if (!StringUtils.hasText(generatedBeanName)) {
+			throw new BeanDefinitionStoreException("Unnamed bean definition specifies neither " +
+					"'class' nor 'parent' nor 'factory-bean' - can't generate bean name");
+		}
+
+		String id = generatedBeanName;
+		if (isInnerBean) {
+			// Inner bean: generate identity hashcode suffix.
+			// 组装名称
+			// 生成名称 + # + 16 进制的一个字符串
+			id = generatedBeanName + GENERATED_BEAN_NAME_SEPARATOR + ObjectUtils.getIdentityHexString(definition);
+		}
+		else {
+			// Top-level bean: use plain class name with unique suffix if necessary.
+			// 唯一beanName设置
+			// // beanName + # + 序号
+			return uniqueBeanName(generatedBeanName, registry);
+		}
+		return id;
+	}
+```
+
+
+
+## uniqueBeanName
+
+```java
+public static String uniqueBeanName(String beanName, BeanDefinitionRegistry registry) {
+   String id = beanName;
+   int counter = -1;
+
+   // Increase counter until the id is unique.
+   while (counter == -1 || registry.containsBeanDefinition(id)) {
+      counter++;
+      // beanName + # + 序号
+      id = beanName + GENERATED_BEAN_NAME_SEPARATOR + counter;
+   }
+   return id;
+}
+```
+
+
+
+
+
+## registerBeanDefinition
+
+```java
+public static void registerBeanDefinition(
+      BeanDefinitionHolder definitionHolder, BeanDefinitionRegistry registry)
+      throws BeanDefinitionStoreException {
+
+   // Register bean definition under primary name.
+   // 获取 beanName
+   String beanName = definitionHolder.getBeanName();
+   // 注册bean definition
+   registry.registerBeanDefinition(beanName, definitionHolder.getBeanDefinition());
+
+   // Register aliases for bean name, if any.
+   // 别名列表
+   String[] aliases = definitionHolder.getAliases();
+   // 注册别名列表
+   if (aliases != null) {
+      for (String alias : aliases) {
+         registry.registerAlias(beanName, alias);
+      }
+   }
+}
+```
+
+
+
+
+
+## registerWithGeneratedName
+
+```java
+public static String registerWithGeneratedName(
+      AbstractBeanDefinition definition, BeanDefinitionRegistry registry)
+      throws BeanDefinitionStoreException {
+
+   // 生成一个 beanName
+   String generatedName = generateBeanName(definition, registry, false);
+   // 注册 bean Definition
+   registry.registerBeanDefinition(generatedName, definition);
+   return generatedName;
+}
+```