add bean definition registry post processor sample in spring boot source code analysis

Author: ipipman

springboot-source-code-analysis/src/main/java/com/example/springboot/source/code/analysis/ioc/ann/MyBeanDefinitionRegistry.java

@@ -0,0 +1,33 @@
+package com.example.springboot.source.code.analysis.ioc.ann;
+
+import com.example.springboot.source.code.analysis.ioc.pojo.Monkey;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.stereotype.Component;
+
+/**
+ * Created by ipipman on 2021/10/16.
+ *
+ * @version V1.0
+ * @Package com.example.springboot.source.code.analysis.ioc.ann
+ * @Description: (通过BeanDefinitionRegistryPostProcessor 进行Bean的注入)
+ * @date 2021/10/16 3:18 下午
+ */
+@Component
+public class MyBeanDefinitionRegistry implements BeanDefinitionRegistryPostProcessor {
+
+    @Override
+    public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry beanDefinitionRegistry) throws BeansException {
+        RootBeanDefinition rootBeanDefinition = new RootBeanDefinition();
+        rootBeanDefinition.setBeanClass(Monkey.class);
+        beanDefinitionRegistry.registerBeanDefinition("monkey", rootBeanDefinition);
+    }
+
+    @Override
+    public void postProcessBeanFactory(ConfigurableListableBeanFactory configurableListableBeanFactory) throws BeansException {
+
+    }
+}

springboot-source-code-analysis/src/main/java/com/example/springboot/source/code/analysis/ioc/service/HelloService.java

@@ -23,7 +23,11 @@ public class HelloService {
      * animal
      */
     @Autowired
-    @Qualifier("myCatFactoryBean") // 如果有多个同类型的Bean，那么用@Qualifier指定Bean的名称后进行注入
+    // 如果有多个同类型的Bean，那么用@Qualifier指定Bean的名称后进行注入
+    //@Qulifier("dog") // 通过@Configuration注解进行Bean注入
+    //@Qualifier("myCatFactoryBean") // 通过FacotryBean<?>接口进行Bean注入
+    //@Qualifier("monkey") // 通过BeanDefinitionRegistryPostProcessor接口进行Bean注入
+
     private Animal animal;