[Spring] 动态加载Bean [转载]

 From: http://blog.csdn.net/buyaore_wo/article/details/8119577

 //将applicationContext转换为ConfigurableApplicationContext  
ConfigurableApplicationContext configurableApplicationContext = (ConfigurableApplicationContext) applicationContext;  
  
// 获取bean工厂并转换为DefaultListableBeanFactory  
DefaultListableBeanFactory defaultListableBeanFactory = (DefaultListableBeanFactory) configurableApplicationContext  
        .getBeanFactory();  
  
// 通过BeanDefinitionBuilder创建bean定义  
BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder  
        .genericBeanDefinition(UserService.class);  
// 设置属性userAcctDAO,此属性引用已经定义的bean:userAcctDAO  
beanDefinitionBuilder  
        .addPropertyReference("userAcctDAO", "UserAcctDAO");  
  
// 注册bean  
defaultListableBeanFactory.registerBeanDefinition("sdfds",  
        beanDefinitionBuilder.getRawBeanDefinition());  

 

 User.java

 

public class User {  
  
    private String username;  
    private String password;  
  
    public String getUsername() {  
        return username;  
    }  
  
    public void setUsername(String username) {  
        this.username = username;  
    }  
  
    public String getPassword() {  
        return password;  
    }  
  
    public void setPassword(String password) {  
        this.password = password;  
    }  
  
}  

 UserService.java

 

 

public class UserService {  
  
    private User user;  
      
      
    public void test(){  
        System.out.println(user.getUsername()+"--------------------");  
    }  
  
    public User getUser() {  
        return user;  
    }  
      
      
  
    public void setUser(User user) {  
        this.user = user;  
    }  
}  

  示例:

 

BeanFactoryAwareBean.java

import org.springframework.beans.BeansException;  
import org.springframework.beans.factory.BeanFactory;  
import org.springframework.beans.factory.BeanFactoryAware;  
import org.springframework.beans.factory.support.BeanDefinitionBuilder;  
import org.springframework.beans.factory.support.DefaultListableBeanFactory;  
import org.springframework.context.ApplicationListener;  
import org.springframework.context.event.ContextRefreshedEvent;  
  
public class BeanFactoryAwareBean implements BeanFactoryAware,  
        ApplicationListener<ContextRefreshedEvent> {  
    private DefaultListableBeanFactory beanFactory;  
  
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {  
        System.out.println("setBeanFactory.........................");  
        this.beanFactory = (DefaultListableBeanFactory) beanFactory;  
    }  
  
    public void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent) {  
        System.out.println("ContextRefreshed...................");  
  
        BeanDefinitionBuilder userBeanDefinitionBuilder = BeanDefinitionBuilder  
                .genericBeanDefinition(User.class);  
        userBeanDefinitionBuilder.addPropertyValue("username", "chinfeng");  
        userBeanDefinitionBuilder.addPropertyValue("password", "123456");  
        beanFactory.registerBeanDefinition("user",  
                userBeanDefinitionBuilder.getRawBeanDefinition());  
  
        BeanDefinitionBuilder usersBeanDefinitionBuilder = BeanDefinitionBuilder  
                .genericBeanDefinition(UserService.class);  
        usersBeanDefinitionBuilder.addPropertyReference("user", "user");  
        beanFactory.registerBeanDefinition("userService",  
                usersBeanDefinitionBuilder.getRawBeanDefinition());  
    }  
}  

 applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">  
    <bean id="beanFactoryAwareBean" class="BeanFactoryAwareBean"></bean>  
</beans>  

 结果:

 

setBeanFactory.........................
ContextRefreshed...................
chinfeng--------------------