Spring_spring自动装配置注解(@Autowired)指定要装配置的参数(@Qualifier)

@Autowired
	a>默认按类型by type
	b>如果想用byName,使用Qulifler
	c>写在private field(第三种注入形式)(不建议,破封装)
	d>如果写在set上,@qualifier需要写在参数上

导入spring注解配置

xmlns:context="http://www.springframework.org/schema/context

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context.xsd">

package com.bjsxd.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;

import com.bjsxd.dao.UserDao;
import com.bjsxd.model.User;

public class UserService {
	private UserDao userDao;

	public UserDao getUserDao() {
		return userDao;
	}

	@Autowired//自动装配
	public void setUserDao(@Qualifier("userDaoImpl")UserDao userDao) {//指定要使用的的bean的ID注入
		this.userDao = userDao;
	}

	public void add(User user) {
		userDao.save(user);
	}
}