使用 spring 的 IoC 实现账户的 CRUD

大致步骤：

• 1.创建数据库
• 2.账户实体类
• 3.编写持久层代码
• 4.账户的持久层实现类
• 5.编写业务层代码
• 6.业务层实现类
• 7.配置文件

基本结构

1.创建数据库

create table account(
id int primary key auto_increment,
name varchar(40),
money float
)character set utf8 collate utf8_general_ci;
insert into account(name,money) values('aaa',1000);
insert into account(name,money) values('bbb',1000);
insert into account(name,money) values('ccc',1000);

2.账户实体类

package com.itheima.domain;

import java.io.Serializable;

/*
* 账户的实体类
* */
public class Account implements Serializable {
    private Integer id;
    private String name;
    private Float money;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Float getMoney() {
        return money;
    }

    public void setMoney(Float money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", money=" + money +
                '}';
    }
}

3.编写持久层代码

package com.itheima.Dao;

import com.itheima.domain.Account;

import java.util.List;

/*
* 账户的持久层接口
* */
public interface IAccountDao {
    /*
     * 查询所有
     * */
    List<Account> findAllAccount();
    /*
     * 查询一个
     * */
    Account findAccountById(Integer accountId);
    /*
     * 保存
     * */
    void saveAccount(Account account);
    /*
     * 更新
     * */
    void updateAccount(Account account);
    /*
    * 删除
    * */
    void deleteAccount(Integer accountId);
}

4.账户的持久层实现类

package com.itheima.Dao.Impl;
/*
* 账户的持久层实现类
* */
import com.itheima.Dao.IAccountDao;
import com.itheima.domain.Account;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import java.util.List;

public class AccountDaoImpl implements IAccountDao {
    private QueryRunner runner;

    public void setRunner(QueryRunner runner) {
        this.runner = runner;
    }

    @Override
    public List<Account> findAllAccount() {
        try {
            return runner.query("select * from account",new BeanListHandler<Account>(Account.class));
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }

    @Override
    public Account findAccountById(Integer accountId) {
        try {
            return runner.query("select * from account where id=?",new BeanHandler<Account>(Account.class),accountId);
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }

    @Override
    public void saveAccount(Account account) {
        try {
             runner.update("insert into account(name,money) values(?,?)",account.getName(),account.getMoney());
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }

    @Override
    public void updateAccount(Account account) {
        try {
            runner.update("update account set name=?,money=? where id=?",account.getName(),account.getMoney(),account.getId());
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }

    @Override
    public void deleteAccount(Integer accountId) {
        try {
            runner.update("delete from account  where id=?",accountId);
        }catch (Exception e){
            throw new RuntimeException(e);
        }
    }
}

5.编写业务层代码

package com.itheima.service;

import com.itheima.domain.Account;

import java.util.List;

/*
* 账户的业务层接口
* */
public interface IAccountService {
    /*
    * 查询所有
    * */
    List<Account> findAllAccount();
    /*
    * 查询一个
    * */
    Account findAccountById(Integer accountId);
    /*
    * 保存
    * */
    void saveAccount(Account account);
    /*
    * 更新
    * */
    void updateAccount(Account account);

    void deleteAccount(Integer accountId);
}

6.业务层实现类

package com.itheima.service.Impl;

import com.itheima.Dao.IAccountDao;
import com.itheima.domain.Account;
import com.itheima.service.IAccountService;

import java.util.List;

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

    public void setAccountDao(IAccountDao accountDao) {
        this.accountDao = accountDao;
    }

    @Override
    public List<Account> findAllAccount() {
        return accountDao.findAllAccount();
    }

    @Override
    public Account findAccountById(Integer accountId) {
        return accountDao.findAccountById(accountId);
    }

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

    @Override
    public void updateAccount(Account account) {
        accountDao.updateAccount(account);
    }

    @Override
    public void deleteAccount(Integer accountId) {
        accountDao.deleteAccount(accountId);
    }
}

7.配置文件：

bean.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--配置Service对象-->
    <bean id="accountService" class="com.itheima.service.Impl.AccountServiceImpl">
        <!--注入dao-->
        <property name="accountDao" ref="accountDao"></property>
    </bean>

    <!--配置Dao对象-->
    <bean id="accountDao" class="com.itheima.Dao.Impl.AccountDaoImpl">
        <!--注入QueryRunner-->
        <property name="runner" ref="runner"></property>
    </bean>

    <!--配置QueryRunner对象-->
    <bean id="runner" class="org.apache.commons.dbutils.QueryRunner" scope="prototype">
        <!--注入数据源-->
        <constructor-arg name="ds" ref="dataSource"></constructor-arg>
    </bean>

    <!--配置数据源-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!--连接数据库的必备信息-->
        <property name="driverClass" value="com.mysql.cj.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/eesy?useSSL=false&serverTimezone=UTC"></property>
        <property name="user" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>
</beans>

8.测试类：

package com.itheima.test;

import com.itheima.domain.Account;
import com.itheima.service.IAccountService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

/*
* 使用Junit单元测试，测试我们的配置
* */
public class AccountServiceTest {

    @Test
    public void testFindAll(){
        //1.获取容器
        ApplicationContext ac=new ClassPathXmlApplicationContext("bean.xml");
        //2.得到业务层对象
        IAccountService as=ac.getBean("accountService",IAccountService.class);
        //3.执行方法
        List<Account> accounts=as.findAllAccount();
        for(Account account:accounts){
            System.out.println(account);
        }

    }
    @Test
    public void testFindOne(){
        //1.获取容器
        ApplicationContext ac=new ClassPathXmlApplicationContext("bean.xml");
        //2.得到业务层对象
        IAccountService as=ac.getBean("accountService",IAccountService.class);
        //3.执行方法
        Account account=as.findAccountById(1);
        System.out.println(account);
    }
    @Test
    public void testSave(){
        Account account=new Account();
        account.setName("test");
        account.setMoney(12345F);
        //1.获取容器
        ApplicationContext ac=new ClassPathXmlApplicationContext("bean.xml");
        //2.得到业务层对象
        IAccountService as=ac.getBean("accountService",IAccountService.class);
        //3.执行方法
        as.saveAccount(account);
    }
    @Test
    public void testUpdate(){
        //1.获取容器
        ApplicationContext ac=new ClassPathXmlApplicationContext("bean.xml");
        //2.得到业务层对象
        IAccountService as=ac.getBean("accountService",IAccountService.class);
        //3.执行方法
        Account account=as.findAccountById(4);
        account.setMoney(23456F);
        as.updateAccount(account);
    }
    @Test
    public void testDelete(){
        //1.获取容器
        ApplicationContext ac=new ClassPathXmlApplicationContext("bean.xml");
        //2.得到业务层对象
        IAccountService as=ac.getBean("accountService",IAccountService.class);
        //3.执行方法
        as.deleteAccount(4);
    }

}

执行结果：

查询所有：

查询id为1的：

插入：(id字段在定义时就是自增的)

我自己测试已经删除过4了，id自增，所以插入的是5

更新：（注意money）

删除id为5的：