模拟spring管理3层

模拟spring管理3层

1. 注解配置版本

package com.fafa.dao.impl;

import com.fafa.dao.UserDao;
import com.fafa.entity.User;
import org.springframework.stereotype.Repository;
//设置名字因为有两个dao实现类，service不知道找哪个
//注入spring的bean容器中
@Repository("DaoMysql")
public class DaoMysql implements UserDao {
    @Override
    public void findUserByID(User user) {
        System.out.println("mysql按id查询");
    }

    @Override
    public void addUser(User user) {
        System.out.println("mysql添加用户");
    }
}

package com.fafa.dao.impl;

import com.fafa.dao.UserDao;
import com.fafa.entity.User;
import org.springframework.stereotype.Repository;
//设置名字因为有两个dao实现类，service不知道找哪个
@Repository("DaoOracle")
public class DaoOracle implements UserDao {
    @Override
    public void findUserByID(User user) {
        System.out.println("oracle按id查询");
    }

    @Override
    public void addUser(User user) {
        System.out.println("oracle添加用户");
    }
}

package com.fafa.service.impl;

import com.fafa.dao.UserDao;
import com.fafa.entity.User;
import com.fafa.service.UserService;
import lombok.Data;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
//注入spring的bean容器中
@Service
//必须提供Data 放bean容器中让ioc接管
@Data
public class UserServiceImple implements UserService {
   //设置使用了哪个dao
   //自动装配
    @Resource(name = "DaoOracle")
    private UserDao userDao;
    @Override
    public void findUserByID(User user) {
        userDao.findUserByID(user);
    }

    @Override
    public void addUser(User user) {
        userDao.addUser(user);
    }
}

package com.fafa.controller;

import com.fafa.entity.User;
import com.fafa.service.UserService;
import lombok.Data;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
//注入spring的bean容器中
@Controller
//必须提供Data 放bean容器中让ioc接管
@Data
public class Usercontroller {
//自动装配
    @Autowired
    private UserService userService;

    public void findUserByID(User user) {
        userService.findUserByID(user);
    }

    public void addUser(User user) {
        userService.addUser(user);
    }
}

config

package com.fafa.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
//声明是个配置类
@Configuration
//作用就是根据定义的扫描路径,把符合扫描规则的类装配到spring容器中
@ComponentScan("com.fafa")
public class BeansConfig {
}

测试

package com.fafa.test;

import com.fafa.config.BeansConfig;
import com.fafa.controller.Usercontroller;
import com.fafa.entity.User;
import org.junit.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringTest {

    @Test
    public void test01(){
    //添加配置文件
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(BeansConfig.class);
        //添加controller类
        Usercontroller usercontroller = context.getBean(Usercontroller.class);
        usercontroller.findUserByID(null);
        
    }
}

2.注解xml配置版本

第一种全注解方法加beans.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: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-4.3.xsd">
        //在 xml 配置了这个标签后，spring 可以自动去扫描 base-pack 下面或者子包下面的 java 文件，如果扫描到有 @Component @Controller@Service 等这些注解的类，则把这些类注册为 bean
    <context:component-scan base-package="com.fafa"/>
    //开启这样就可以使用 @ Resource 、@ PostConstruct、@ PreDestroy、@PersistenceContext、@Autowired、@Required 等注解了，就可以实现自动注入 注册这 4 个 BeanPostProcessor 的作用，就是为了你的系统能够识别相应的注解。
    <context:annotation-config/>

</beans>

测试

package com.fafa.test;

import com.fafa.controller.Usercontroller;
import com.fafa.entity.User;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringTest {

    @Test
    public void test01(){
       //beans.xml文件
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        //controller类
        Usercontroller bean = context.getBean(Usercontroller.class);
        bean.findUserByID(new User(2,"dafa"));

    }

}

纯配置文件方式（不建议）

导入包

    4.0.0

    com.fafa
    spring02
    1.0-SNAPSHOT
    
        4.12
        3.2.8
        5.1.44
        1.6.6
        4.3.14.RELEASE
        1.18.0
    

    
        
            org.projectlombok
            lombok
            ${lombok.version}
        
        
        
            org.springframework
            spring-context
            ${spring.version}
        
        
            org.springframework
            spring-context-support
            ${spring.version}
        
        
        
            org.springframework
            spring-core
            ${spring.version}
        
        
        
            org.springframework
            spring-beans
            ${spring.version}
        
        
        
            org.springframework
            spring-expression
            ${spring.version}
        
        
        
            junit
            junit
            ${junit.version}
            test
        
        
        
            org.slf4j
            slf4j-log4j12
            1.6.6
        
    

    
        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                3.2
                
                    1.8
                    1.8
                    UTF-8
                
            
        
    

package com.fafa.entity;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class User {
    private Integer id;
    private String name;
}

编写三层
1.dao层

package com.fafa.dao;

import com.fafa.entity.User;

public interface UserDao {
    public void findUserByID(User user);
    public void addUser(User user);

}

package com.fafa.dao.impl;

import com.fafa.dao.UserDao;
import com.fafa.entity.User;

public class DaoMysql implements UserDao {
    @Override
    public void findUserByID(User user) {
        System.out.println("mysql按id查询");
    }

    @Override
    public void addUser(User user) {
        System.out.println("mysql添加用户");
    }
}

package com.fafa.dao.impl;

import com.fafa.dao.UserDao;
import com.fafa.entity.User;

public class DaoOracle implements UserDao {
    @Override
    public void findUserByID(User user) {
        System.out.println("oracle按id查询");
    }

    @Override
    public void addUser(User user) {
        System.out.println("oracle添加用户");
    }
}

2.service层

package com.fafa.service;

import com.fafa.entity.User;

public interface UserService {
    public void findUserByID(User user);
    public void addUser(User user);

}

package com.fafa.service.impl;

import com.fafa.dao.UserDao;
import com.fafa.entity.User;
import com.fafa.service.UserService;
import lombok.Data;

@Data
public class UserServiceImple implements UserService {
    private UserDao userDao;
    @Override
    public void findUserByID(User user) {
        userDao.findUserByID(user);
    }

    @Override
    public void addUser(User user) {
        userDao.addUser(user);
    }
}

3.controller层

package com.fafa.controller;

import com.fafa.entity.User;
import com.fafa.service.UserService;
import lombok.Data;

@Data
public class Usercontroller {
    private UserService userService;

    public void findUserByID(User user) {
        userService.findUserByID(user);
    }

    public void addUser(User user) {
        userService.addUser(user);
    }
}

beans.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="DaoMysql" class="com.fafa.dao.impl.DaoMysql">bean>
    <bean id="DaoOracle" class="com.fafa.dao.impl.DaoOracle">bean>

    <bean id="userService" class="com.fafa.service.impl.UserServiceImple">
        <property name="userDao" ref="DaoOracle">property>
    bean>

    <bean id="userController" class="com.fafa.controller.Usercontroller" >
        <property name="userService" ref="userService">property>
    bean>
beans>

测试

package com.fafa.test;

import com.fafa.controller.Usercontroller;
import com.fafa.entity.User;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringTest {

    @Test
    public void test01(){

        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
        Usercontroller bean = context.getBean(Usercontroller.class);
        bean.findUserByID(User.builder().id(1).name("fafa").build());

    }
}