@@ -17,11 +17,17 @@
 @Component
 public class MyFactoryBean implements FactoryBean<Animal> {
 
+    /**
+     * 返回要注入的类
+     */
     @Override
     public Animal getObject() throws Exception {
         return new Cat();
     }
 
+    /**
+     * 获取要注入类的类型
+     */
     @Override
     public Class<?> getObjectType() {
         return Animal.class;
@@ -31,4 +37,5 @@ public Class<?> getObjectType() {
     public boolean isSingleton() {
         return FactoryBean.super.isSingleton();
     }
+
 }
@@ -0,0 +1,98 @@
+### 通过Java配置Bean的几种方式
+
+#### 1.通过@Configuration注解注入Bean的方式
+
+```java
+@Configuration
+public class MyBeanConfiguration {
+
+    /**
+     * 通过 @Configuration注解 注入一个Bean
+     */
+    @Bean("dog")
+    public Animal getDog() {
+        return new Dog();
+    }
+
+}
+```
+
+
+
+#### 2.通过实现FactoryBean<?>接口的方式注入Bean
+
+```java
+@Component
+public class MyFactoryBean implements FactoryBean<Animal> {
+
+    /**
+     * 返回要注入的类 
+     */
+    @Override
+    public Animal getObject() throws Exception {
+        return new Cat();
+    }
+
+    /**
+     * 获取要注入类的类型 
+     */
+    @Override
+    public Class<?> getObjectType() {
+        return Animal.class;
+    }
+
+    @Override
+    public boolean isSingleton() {
+        return FactoryBean.super.isSingleton();
+    }
+    
+}
+```
+
+
+
+#### 3.通过实现BeanDefinitionRegistryPostProcessor接口的方式注入Bean
+
+```java
+@Component
+public class MyBeanDefinitionRegistry implements BeanDefinitionRegistryPostProcessor {
+
+    /**
+     * 通过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 {
+
+    }
+}
+```
+
+
+
+#### 4.通过实现ImportBeanDefinitionRegistrar接口的方式注入Bean
+
+```java
+public class MyImportBeanDefinitionRegistrar implements ImportBeanDefinitionRegistrar {
+
+    /**
+     * 通过ImportBeanDefinitionRegistrar注入Bean
+     */
+    @Override
+    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
+        RootBeanDefinition rootBeanDefinition = new RootBeanDefinition();
+        rootBeanDefinition.setBeanClass(Bird.class);
+        registry.registerBeanDefinition("bird", rootBeanDefinition);
+    }
+}
+
+```
+
+> 使用时：用 @Import(MyImportBeanDefinitionRegistrar.class) 进行注入
+