本节内容
本节将结合数据库的操作使用讲解IOC的实际案例使用。
数据库准备
首先要在本机安装MYSQl,如果装的是8.0+的mysql版本，在写数据库的时候要注意了，可能需要花点时间适配一下。
MAVEN配置
<?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.sankuai</groupId>
<artifactId>lujuan</artifactId>
<version>1.0-SNAPSHOT</version>
<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>8.0.11</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>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>5.0.2.RELEASE</version>
</dependency>
</dependencies>
</project>在这个配置中，我们为了进行数据库操作要导入一个mysql驱动，一个commons-dbutils用来创建数据库的，c3p0用来操作数据库链接池的（虽然不是很明白为什么链接池不是在commons-dbutils中一起封装的）。
数据库配置
insert into account(name,money)values('aaa',1000);
insert into account(name,money)values('bbb',1000);
insert into account(name,money)values('ccc',1000);
然后我们就有链接数据库的内容了。
代码展示-测试文件
package com.lujuan;
import com.lujuan.domain.Account;
import com.lujuan.service.impl.AccountServiceImpl;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import java.util.List;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:bean.xml")
public class AccountServiceTest {
@Autowired
private AccountServiceImpl ac;
@Test
public void testFindAll(){
List<Account> accounts = ac.findAllAccount();
for(Account account:accounts)
System.out.println(account.toString());
}
@Test
public void testFindAccountById() {
Account account = ac.findAccountById(1);
System.out.println(account);
}
@Test
public void testAddAccount() {
Account account = new Account();
account.setName("ddd");
account.setMoney(2000f);
ac.addAccount(account);
}
@Test
public void testDeleteAccountById() {
ac.deleteAccountById(1);
}
@Test
public void testUpdateAccount() {
Account account = ac.findAccountById(4);
account.setName("eeee");
account.setMoney(3333f);
ac.updateAccount(account);
}
}
代码展示-bean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"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">
<!--告知spring在创建容器时要扫描的包，配置所需要的标签不是在bean约束中，
而是在一个名称为context的名称空间和约束中-->
<context:component-scan base-package="com.lujuan"/>
<bean id = "accountService" class="com.lujuan.service.impl.AccountServiceImpl">
<property name="accountDao" ref ="accountDao"> </property>
</bean>
<bean id = "accountDao" class="com.lujuan.dao.imp.AccountDaoImpl">
<property name="queryRunner" ref = "queryRunner"> </property>
</bean>
<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/eesy?characterEncoding=utf8"> </property>
<property name="user" value="root"> </property>
<property name="password" value="Admin@123"> </property>
</bean>
</beans>在这个里面根据一层一层的调用关系进行了相关的bean文件配置，但是其实我还是不是很理解有关数据库的一些配置规则。
Dao代码文件
package com.lujuan.dao.imp;
import com.lujuan.dao.IAccountDao;
import com.lujuan.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;
/**
* @项目: spring-learn-demo
* @描述:
* @作者: lujuan03
* @创建日期: 2020-03-28
**/
public class AccountDaoImpl implements IAccountDao {
private QueryRunner queryRunner;//这是commons.dbutils提供的
public void setQueryRunner(QueryRunner queryRunner) {
this.queryRunner = queryRunner;
}
public List<Account> findAllAccount() {
List<Account> reV = null;
try{
//查询之后顺便映射为实体类
reV = queryRunner.query("select * from account", new BeanListHandler<Account>(Account.class));
}catch (Exception e){
throw new RuntimeException(e);
}
return reV;
}
public Account findAccountById(Integer id) {
Account reV = null;
try{
reV = queryRunner.query("select * from account where id = ?", new BeanHandler<Account>(Account.class), id);
}catch (Exception e){
throw new RuntimeException(e);
}
return reV;
}
public void addAccount(Account account) {
try{
queryRunner.update("insert into account(name, money) values (?, ?)", account.getName(), account.getMoney());
}catch (Exception e){
throw new RuntimeException(e);
}
}
public void deleteAccountById(Integer id) {
try{
queryRunner.update("delete from account where id = ?", id);
}catch (Exception e){
throw new RuntimeException(e);
}
}
public void updateAccount(Account account) {
try{
queryRunner.update("update account set name= ?, money = ? where id = ?", account.getName(), account.getMoney(), account.getId());
}catch (Exception e){
throw new RuntimeException(e);
}
}
}
Dao的接口文件
package com.lujuan.dao;
import com.lujuan.domain.Account;
import java.util.List;
public interface IAccountDao {
List<Account> findAllAccount();
Account findAccountById(Integer id);
void addAccount(Account account);
void deleteAccountById(Integer id);
void updateAccount(Account account);
}servie接口文件
package com.lujuan.service;
import com.lujuan.domain.Account;
import java.util.List;
public interface IAccountService {
List<Account> findAllAccount();
Account findAccountById(Integer id);
void addAccount(Account account);
void deleteAccountById(Integer id);
void updateAccount(Account account);
}
service实现文件
package com.lujuan.service.impl;
import com.lujuan.dao.IAccountDao;
import com.lujuan.domain.Account;
import com.lujuan.service.IAccountService;
import org.springframework.stereotype.Service;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import java.util.*;
/**
* @项目: spring-learn-demo
* @描述:
* @作者: lujuan03
* @创建日期: 2020-03-28
**/
//@Component(value="accountService")
//@Controller
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 id) {
return accountDao.findAccountById(id);
}
public void addAccount(Account account) {
accountDao.addAccount(account);
}
public void deleteAccountById(Integer id) {
accountDao.deleteAccountById(id);
}
public void updateAccount(Account account) {
accountDao.updateAccount(account);
}
public void saveAccount() {
System.out.println("AccountServiceImpl: saveAccount");
}
@PostConstruct
public void init(){
System.out.println("init......");
}
@PreDestroy
public void destroy(){
System.out.println("destroy......");
}
}运行结果
执行我们写的test文件就可以检查我们这个IOC实例项目了。
不明白的地方
我现在对数据库的连接池以及对连接池对使用真的是一头蒙蔽，还有什么事务管理，更是不知道是什么。
但是按照教程交给我们的那样，第一个spring的二层架构的项目完成，执行没有问题。
至于其他的内容待学完这个课程继续深究。
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