下面我们来写一下基于XML的IOC案例
Maven工程
在src、main、java下新建com.itheima包,
建立一个service包,在包下新建一个接口IAccountService,
账户的业务层接口,方法都是查询所有、查询一个、保存、修改、删除。
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);
//修改
    void updateAccount(Account account);
//删除
    void deleteAccount(Integer accountId);
}
在com.itheima下新建一个包domain,在domain下新建一个类Account,账户实体类
对了,在这之前在mysql中已经创建了一个数据库
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);

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 +
                '}';
    }
}

在com.itheima下新建一个包dao,在dao下有一个接口IAccountDao,

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);
//修改
    void updateAccount(Account account);
//删除
    void deleteAccount(Integer accountId);
}
我们的持久层技术选型是dbutils。
我们在dao包下新建一个包impl,在impl下新建AccountDaoImpl,
package com.itheima.dao.impl;

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;
    }

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

    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);
        }
    }

    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);
        }

    }

    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);
        }
    }

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

    }
}

在service层下新建一个类impl.AccountServiceImpl,
package com.itheima.service.impl;

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

import java.util.List;

public class AccountServiceImpl implements IAccountService {

    private IAccountDao accountDao;

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

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

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

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

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

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

我们需要在resources中的bean.xml中配置Service、配置Dao、配置QueryRunner
<?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">
    <!--配置Service-->
    <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-->
    <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.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/eesy"></property>
        <property name="user" value="root"></property>
        <property name="password" value="123"></property>
    </bean>
</beans>
在test包下新建一个AccountServiceTest类,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.security.AccessControlContext;
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);
        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);
        Account account = as.findAccountById(4);
        account.setName("test11");
        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);

        as.deleteAccount(4);

    }
}

在pom.xml中我们需要注册的依赖有spring、dbutils、mysql、junit、c3p0。
<?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>com.itheima</groupId>
    <artifactId>day02_eesy_02account_xmlioc</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.0.2.RELEASE</version>
        </dependency>


        <dependency>
            <groupId>commons-dbutils</groupId>
            <artifactId>commons-dbutils</artifactId>
            <version>1.4</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.32</version>
        </dependency>

        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

    </dependencies>


</project>