2 环境搭建

2.1 拷贝 jar 包

2.2 创建数据库和编写实体类

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);

/**
* 账户的实体类
* @Version 1.0
*/
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;}
}

2.3 编写持久层代码

账户的持久层接口

/**
* 账户的持久层接口
* @Version 1.0
*/
public interface IAccountDao {/*** 保存* @param account*/void save(Account account);/*** 更新* @param account*/void update(Account account);/*** 删除* @param accountId*/void delete(Integer accountId);/*** 根据 id 查询* @param accountId* @return*/Account findById(Integer accountId);/*** 查询所有* @return*/List<Account> findAll();
}

账户的持久层实现类

/**
* 账户的持久层实现类
* @Version 1.0
*/
public class AccountDaoImpl implements IAccountDao {private DBAssit dbAssit;public void setDbAssit(DBAssit dbAssit) {this.dbAssit = dbAssit;}@Overridepublic void save(Account account) {dbAssit.update("insert into account(name,money)values(?,?)",account.getName(),account.getMoney());}@Overridepublic void update(Account account) {dbAssit.update("update account set name=?,money=? where id=?",account.getName(),account.getMoney(),account.getId());}@Overridepublic void delete(Integer accountId) {dbAssit.update("delete from account where id=?",accountId);}@Overridepublic Account findById(Integer accountId) {return dbAssit.query("select * from account where id=?",new BeanHandler<Account>(Account.class),accountId);}@Overridepublic List<Account> findAll() {return dbAssit.query("select * from account where id=?",new BeanListHandler<Account>(Account.class));}
}

2.4 编写业务层代码

账户的业务层接口

public interface IAccountService {/*** 保存账户* @param account*/void saveAccount(Account account);/*** 更新账户* @param account*/void updateAccount(Account account);/*** 删除账户* @param account*/void deleteAccount(Integer accountId);/*** 根据 id 查询账户* @param accountId* @return*/Account findAccountById(Integer accountId);/*** 查询所有账户* @return*/List<Account> findAllAccount();
}

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;}@Overridepublic void saveAccount(Account account) {accountDao.save(account);}@Overridepublic void updateAccount(Account account) {accountDao.update(account);}@Overridepublic void deleteAccount(Integer accountId) {accountDao.delete(accountId);}@Overridepublic Account findAccountById(Integer accountId) {return accountDao.findById(accountId);}@Overridepublic List<Account> findAllAccount() {return accountDao.findAll();}
}

2.5 创建并编写配置文件

<?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/beanshttp://www.springframework.org/schema/beans/spring-beans.xsd">
</beans>

3 配置步骤

<?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/beanshttp://www.springframework.org/schema/beans/spring-beans.xsd"><!-- 配置 service --><bean id="accountService"class="com.itheima.service.impl.AccountServiceImpl"><property name="accountDao" ref="accountDao"></property></bean><!-- 配置 dao --><bean id="accountDao" class="com.itheima.dao.impl.AccountDaoImpl"><property name="dbAssit" ref="dbAssit"></property></bean><!-- 配置 dbAssit 此处我们只注入了数据源，表明每条语句独立事务--><bean id="dbAssit" class="com.itheima.dbassit.DBAssit"><property name="dataSource" ref="dataSource"></property></bean><!-- 配置数据源 --><bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"><property name="driverClass" value="com.mysql.jdbc.Driver"></property><property name="jdbcUrl" value="jdbc:mysql:///spring_day02"></property><property name="user" value="root"></property><property name="password" value="1234"></property></bean>
</beans>

4 测试案例

4.1 测试类代码

public class AccountServiceTest {/*** 测试保存*/@Testpublic void testSaveAccount() {Account account = new Account();account.setName("黑马程序员");account.setMoney(100000f);ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");IAccountService as = ac.getBean("accountService",IAccountService.class);as.saveAccount(account);}/*** 测试查询一个*/@Testpublic void testFindAccountById() {ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");IAccountService as = ac.getBean("accountService",IAccountService.class);Account account = as.findAccountById(1);System.out.println(account);}/*** 测试更新*/@Testpublic void testUpdateAccount() {ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");IAccountService as = ac.getBean("accountService",IAccountService.class);Account account = as.findAccountById(1);account.setMoney(20301050f);as.updateAccount(account);}/*** 测试删除*/@Testpublic void testDeleteAccount() {ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");IAccountService as = ac.getBean("accountService",IAccountService.class);as.deleteAccount(1);}/*** 测试查询所有*/@Testpublic void testFindAllAccount() {ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");IAccountService as = ac.getBean("accountService",IAccountService.class);List<Account> list = as.findAllAccount();for(Account account : list) {System.out.println(account);}}
}

4.2 分析测试了中的问题
- 通过上面的测试类，可以看出，每个测试方法都重新获取了一次 spring 的核心容器，造成了不必要的重复代码，增加了开发的工作量。这种情况，在开发中应该避免发生。
- 可以考虑把容器的获取定义到类中去。例如：
- ```
public class AccountServiceTest {private ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");private IAccountService as = ac.getBean("accountService",IAccountService.class);
}
```
- 这种方式虽然能解决问题，但是扔需要写代码来获取容器。