spring的bean的注入

Spring容器成功启动的三大要件分别是：Bean定义信息、Bean实现类以及Spring本身。如果采用基于XML的配置，Bean定义信息和Bean实现类本身是分离的，而采用基于注解的配置方式时，Bean定义信息即通过在Bean实现类上标注注解实现。

 

@Component("userDao")

效果等同于：

属性注入

package com.baobaotao.anno;
import org.springframework.beans.factory.BeanNameAware;
public class LogonService implements BeanNameAware{
    private LogDao logDao;
    private UserDao userDao;
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    public void setLogDao(LogDao logDao) {
        this.logDao = logDao;
    }
    public LogDao getLogDao() {
        return logDao;
    }
    public UserDao getUserDao() {
        return userDao;
    }
        public void setBeanName(String beanName) {
        System.out.println("beanName:"+beanName);        
    }
        public void initMethod1(){
        System.out.println("initMethod1");
    }
    public void initMethod2(){
        System.out.println("initMethod2");
    }

  }

等同于：
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.0.xsd"
       default-autowire="byName"
         >
   
   
   
       
       
   

构造方法注入：

package com.baobaotao.anno;


import org.springframework.beans.factory.BeanNameAware;


public class LogonService implements BeanNameAware{


    public LogonService(){}


    public LogonService(LogDao logDao, UserDao userDao) {
        this.logDao = logDao;
        this.userDao = userDao;
    }


    private LogDao logDao;


    private UserDao userDao;


    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }


    public void setLogDao(LogDao logDao) {
        this.logDao = logDao;
    }
    
    public LogDao getLogDao() {
        return logDao;
    }
    public UserDao getUserDao() {
        return userDao;
    }
    
    public void setBeanName(String beanName) {
        System.out.println("beanName:"+beanName);        
    }
    
    public void initMethod1(){
        System.out.println("initMethod1");
    }
    public void initMethod2(){
        System.out.println("initMethod2");
    }
    

}

bean.xml注入：

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.0.xsd"
       default-autowire="byName">