使用 spring 的 IOC 实现对象的管理 使用 dbutils作为持久层解决方案 使用 c3p0 数据源
XML方式
引入依赖
Spring，dbutils，Mysql，C3P0，Junit
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.2.8.RELEASE</version>
</dependency>
<dependency>
<groupId>commons-dbutils</groupId>
<artifactId>commons-dbutils</artifactId>
<version>1.7</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.6</version>
</dependency>
<dependency>
<groupId>c3p0</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.1.2</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
</dependency>
</dependencies>
建表
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) ;
实体类
Account.java
public class Account implements Serializable {
private Integer id;
private String name;
private Float money;
//生成set/get
}
Service接口及实现类
//service接口
public interface IAccountService {
List<Account> findAllAccount();
}
//实现类
public class AccountServiceImpl implements IAccountService {
private IAccountDao accountDao;
//生成set/get
public List<Account> findAllAccount() {
return accountDao.findAllAccount();
}
}
Dao接口及实现类
//DAO接口
public interface IAccountDao {
List<Account> findAllAccount();
}
//实现类
public class AccountDaoImpl implements IAccountDao {
private QueryRunner queryRunner;
//生成set/get
public List<Account> findAllAccount() {
try {
return queryRunner.query("select * from account",
new BeanListHandler<Account>(Account.class)
);
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
Spring 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">
<bean id="accountService" class="com.mg.service.impl.AccountServiceImpl">
<property name="accountDao" ref="accountDao"></property>
</bean>
<bean id="accountDao" class="com.mg.dao.impl.AccountDaoImpl">
<property name="queryRunner" ref="queryRunner"></property>
</bean>
<!--单例时，多个DAO同时使用会产生线程安全问题，所以改为多例-->
<bean id="queryRunner" class="org.apache.commons.dbutils.QueryRunner" scope="prototype">
<constructor-arg name="ds" ref="dataSource"></constructor-arg>
</bean>
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/spring"></property>
<property name="user" value="root"></property>
<property name="password" value="root"></property>
</bean>
</beans>
测试使用
public class MyTest {
@Test
public void test1() {
ApplicationContext ac = new ClassPathXmlApplicationContext("bean.xml");
IAccountService accountService = ac.getBean("accountService", IAccountService.class);
List<Account> accounts = accountService.findAllAccount();
for(Account account:accounts) {
System.out.println(account);
}
}
}
注解方式
注：此处的注解方式并不彻底，还会存在Spring的配置文件。彻底的解决方式会在下篇讲解其他注解中进行实现。
引入依赖
同xml方式
建表
同xml方式
实体类
同xml方式
Service接口及实现类
//service接口,同xml方式
public interface IAccountService {
List<Account> findAllAccount();
}
//实现类，加入相应注解
@Service("accountService")
public class AccountServiceImpl implements IAccountService {
@Autowired
private IAccountDao accountDao;
public List<Account> findAllAccount() {
return accountDao.findAllAccount();
}
}
DAO接口及实现类
//DAO接口,同xml方式
public interface IAccountDao {
List<Account> findAllAccount();
}
//实现类，加入相应注解
@Repository("accountDao")
public class AccountDaoImpl implements IAccountDao {
@Autowired
private QueryRunner queryRunner;
public List<Account> findAllAccount() {
try {
return queryRunner.query("select * from account",
new BeanListHandler<Account>(Account.class)
);
} catch (SQLException e) {
throw new RuntimeException(e);
}
}
}
Spring配置文件
bean.xml
<?xml version="1.0" encoding="UTF-8"?>
<!--导入约束时需要多导入一个 context 名称空间下的约束-->
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
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
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!--需要扫描的包-->
<context:component-scan base-package="com.mg"></context:component-scan>
<bean id="queryRunner" class="org.apache.commons.dbutils.QueryRunner" scope="prototype">
<constructor-arg name="ds" ref="dataSource"></constructor-arg>
</bean>
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/spring"></property>
<property name="user" value="root"></property>
<property name="password" value="root"></property>
</bean>
</beans>
测试使用
同xml方式
