16.Spring之Annotation(基本使用)

想要将某一个类交给Spring来进行管理
可以在类上面写一个万能注解@Component 组件
@Component(value=”id名称”) 如果value不写 默认的值是”” 但是肯定不能用这个””作为id
如果不写的话，对象的获取 类名字驼峰式

@Controller
@Service
@Repository

@Autowired
对象中的属性自动注入

StudentController

package controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import service.StudentService;
/**
 * 控制层
 * 1.继承父类  2.重写方法  3.参数  返回值  异常。。。。
 * 封装-----没有继承  方法随便   参数随便(IOC DI)  返回值(void String ModelAndView)  没有异常
 *
 * 控制层方法做的事情
 * 1.接收请求参数信息
 * 2.调用业务层的小弟支持我
 * 3.根据业务层执行  最终控制响应信息
 */
@Controller("studentController")
public class StudentController {
    //属性  业务层小弟
    private StudentService service;
    @Autowired
    public void setService(StudentService service) {
        this.service = service;
    }
    //自己控制方法
    public void contollerMethod(String ssex) {
        System.out.println("controllerMethod");
        service.serviceMethod(ssex);
    }
}

StudentService

package service;
import dao.StudentDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
 * 业务层
 * 为了controller做业务支持
 * <p>
 * 业务层中的方法主要做   比较  计算  判断  等核心业务
 * 1.参数通常是controller给的
 * 2.核心业务是自己处理
 * 需要数据的支持----DAO
 */
@Service("studentService")
public class StudentService {
    //属性 DAO小弟
    private StudentDao dao;
    @Autowired
    public void setDao(StudentDao dao) {
        this.dao = dao;
    }
    //自己业务方法
    public void serviceMethod(String ssex) {
        System.out.println("serviceMethod");
        dao.select(ssex);
    }
}

StudentDao

package dao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import java.util.List;
/**
 * 数据持久层
 *
 *          操作数据库读写     JDBC+SQL
 */
@Repository("studentDao")
public class StudentDao {
    //属性 小弟JdbcTemplate     SqlSession
    private JdbcTemplate jdbcTemplate;
    @Autowired
    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }
    //dao自己的方法
    public void select(String ssex){
        System.out.println("daoMethod");
        String sql = "select * from student where ssex = ?";
        List list = jdbcTemplate.queryForList(sql,ssex);
        for(int i=0;i<list.size();i++){
            System.out.println(list.get(i));
        }
    }
}

TestMain

package test;
import controller.StudentController;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestMain {
    public static void main(String[] args) {
        BeanFactory factory = new ClassPathXmlApplicationContext("ApplicationContext.xml");
        StudentController controller = (StudentController) factory.getBean("studentController");
        controller.contollerMethod("男");
    }
}

ApplicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xsi:schemaLocation="http://www.springframework.org/schema/beans
    https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context">
    <!--告知扫描包-->
    <context:component-scan base-package="controller,service,dao"/>
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/newtest?useSSL=false&amp;characterEncoding=UTF-8"></property>
        <property name="username" value="root"></property>
        <property name="password" value="cy414ljh212,,,"></property>
    </bean>
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
</beans>