spring_spring注解资源@Resource、组件注解@Component-蒲公英云

spring_spring注解资源@Resource、组件注解@Component

@Resource(重要)
    a>默认按名称,名称找不到,按类型
    b>可以指定特定名称
    c>推荐使用
    d>不足:如果没有源码,就无法运用annotation,只能使用xml
@Componert
    a>初如化的名字默认为类名首字母小写
    b>可以指定初始化bean的名字

@Resource

<?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:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context.xsd">
    <context:annotation-config />
    <bean id="userDaoImpl" class="com.bjsxd.dao.impl.UserDaoImpl">
    </bean>
    <bean id="userDaoImpl2" class="com.bjsxd.dao.impl.UserDaoImpl">
    </bean>
    <bean id="userService" class="com.bjsxd.service.UserService">
    </bean>
</beans>

对set方法进行注入

package com.bjsxd.service;
import javax.annotation.Resource;
import com.bjsxd.dao.UserDao;
import com.bjsxd.model.User;
public class UserService {
    private UserDao userDao;
    public UserDao getUserDao() {
        return userDao;
    }
    @Resource(name="userDaoImpl2")
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    public void add(User user) {
        userDao.save(user);
    }
}

@Component

自动扫描注入

<?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:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context.xsd">
    <context:annotation-config />
    <context:component-scan base-package="com.bjsxt" />
</beans>
package com.bjsxt.dao.impl;
import org.springframework.stereotype.Component;
import com.bjsxt.dao.UserDao;
import com.bjsxt.model.User;
@Component("userDaoImpl")
public class UserDaoImpl implements UserDao{
    @Override
    public void save(User user) {
        System.out.println("user save!");
    }
}
package com.bjsxt.service;
import javax.annotation.Resource;
import org.springframework.stereotype.Component;
import com.bjsxt.dao.UserDao;
import com.bjsxt.model.User;
@Component("userService")
public class UserService {
    private UserDao userDao;
    public UserDao getUserDao() {
        return userDao;
    }
    @Resource(name="userDaoImpl")
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    public void add(User user) {
        userDao.save(user);
    }
}