表现层-业务层-持久层（spring容器版）

 

 

package com.example.ui;


import com.example.factory.BeanFactory;
import com.example.service.IAccountService;
import com.example.service.impl.AccountServiceImpl;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * 模拟一个表现层，用于调用业务层
 */
public class Client {
    /**
     * 获取spring的Ioc核心容器，并根据id获取对象
     * @param args
     */
    public static void main(String[] args) {

        IAccountService as= BeanFactory.getBean("accountService",IAccountService.class);

        as.saveAccount();
    }
}

package com.example.factory;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class BeanFactory {
    private static ApplicationContext ac=new ClassPathXmlApplicationContext("beans.xml");

    public static <T> T getBean(String beanId,Class<T> tClass){
        return ac.getBean(beanId,tClass);
    }
}

package com.example.service;

/**
 * 账户业务层接口
 */
public interface IAccountService {

    /**
     * 模拟保存账户
     */
    void saveAccount();
}

package com.example.service.impl;

import com.example.dao.impl.AccountDaoImpl;
import com.example.factory.BeanFactory;
import com.example.service.IAccountService;
import com.example.dao.IAccountDao;


/**
 * 账户的业务层实现类
 */
public class AccountServiceImpl implements IAccountService {

    private IAccountDao accountDao= new AccountDaoImpl();

    @Override
    public void saveAccount() {
        accountDao.saveAccount();
    }
}

package com.example.dao;

/**
 * 账户的持久层接口
 */
public interface IAccountDao {

    /**
     * 模拟保存账户
     */
    void saveAccount();
}

package com.example.dao.impl;

import com.example.dao.IAccountDao;

/**
 * 账户的持久层实现类
 */
public class AccountDaoImpl implements IAccountDao {
    @Override
    public void saveAccount(){
        System.out.println("保存了账户");
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<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
        https://www.springframework.org/schema/beans/spring-beans.xsd">
    <!--把对象的创建交给spring来管理-->

   
    <bean id="accountService" class="com.example.service.impl.AccountServiceImpl"></bean>
</beans>

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>spring</artifactId>
    <version>1.0-SNAPSHOT</version>

    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.7.RELEASE</version>
        </dependency>
    </dependencies>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>14</java.version>
        <maven.compiler.source>14</maven.compiler.source>
        <maven.compiler.target>14</maven.compiler.target>
        <encoding>UTF-8</encoding>
    </properties>
    <repositories>
        <repository>
            <id>alimaven</id>
            <name>aliyun maven</name>
            <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>
</project>