因为只有c3p0数据库没有starter,所以本文描述的是c3p0的starter,如果你想替换成其他的连接池,改下配置即可。
官方的开发starter标准推荐有3个模块:
然后提一下artifactId的命名问题,Spring 官方 Starter通常命名为spring-boot-starter-{name} 如 spring-boot-starter-web, Spring官方建议非官方Starter命名应遵循{name}-spring-boot-starter的格式。
首先创建一个自动配置模块,命名为c3p0-spring-boot-starter-autoconfigure,添加以下依赖:
<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">
<parent>
<artifactId>custom-spring-start-parentartifactId>
<groupId>com.edugroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>c3p0-spring-boot-starter-autoconfigureartifactId>
<dependencies>
// 添加此依赖,那些条件注解才可以使用,最好设置为 optional 为 true
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-test-autoconfigureartifactId>
<optional>trueoptional>
dependency>
// c3p0 连接池依赖
<dependency>
<groupId>com.mchangegroupId>
<artifactId>c3p0artifactId>
<version>0.9.5.3version>
dependency>
// 自动生成实体类 get set 注解,可要可不要
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
dependency>
dependencies>
project>
在创建一个autoconfigure包(包名没要求),在包下面创建C3p0的自动配置类(官方推荐自动配置类以AutoConfiguration结尾),文件名为C3p0AutoConfiguration。
// 首先告诉spring boot 这是一个配置类
@Configuration
// 这个注解的意思是,当这个Spring boot 项目中有 DataSource 这个类时,此配置类才生效
@ConditionalOnClass(DataSource.class)
public class C3p0AutoConfiguration {
@Bean
// 这个注解的意思是当spring容器中没有名字叫做dataSource类型为DataSource时才注册
@ConditionalOnMissingBean
public DataSource dataSource() throws Exception{
// 创建一个 c3p0 的连接池
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass("com.mysql.jdbc.Driver");
dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/demo");
dataSource.setUser("root");
dataSource.setPassword("root");
return dataSource;
}
}
并且要在resource文件夹下创建一个META-INF文件夹,在文件夹下创建一个spring.factories文件,里面写上一行代码
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
autoconfigure.C3p0AutoConfiguration //你的自动配置类的全称
到此自动配置类已经可以了,但是现在又有一个新的问题,用户的数据库配置不可能自己写死啊,所以还得写个配置文件,读取配置文件里的内容进行配置。在autoconfigure包下创建一个c3p0的读取配置类。
@Data
@ConfigurationProperties(prefix = "c3p0")
public class C3p0Properties {
private String driver;
private String url;
private String username;
private String password;
}
并且自动配置类也得改变
@Configuration
@ConditionalOnClass(DataSource.class)
@EnableConfigurationProperties(C3p0Properties.class)
public class C3p0AutoConfiguration {
@Autowired
private C3p0Properties c3p0Properties;
@Bean
@ConditionalOnMissingBean
public DataSource dataSource() throws Exception{
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass(c3p0Properties.getDriver());
dataSource.setJdbcUrl(c3p0Properties.getUrl());
dataSource.setUser(c3p0Properties.getUsername());
dataSource.setPassword(c3p0Properties.getPassword());
return dataSource;
}
}
现在既能自定义一个c3p0的连接池,又能读取配置文件信息,所以自动配置类结束。
创建一个c3p0-spring-boot-starter模块,这个模块只管理依赖。
<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">
<parent>
<artifactId>custom-spring-start-parentartifactId>
<groupId>com.edugroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>c3p0-spring-boot-starterartifactId>
<dependencies>
//自动配置模块所需依赖
<dependency>
<groupId>com.mchangegroupId>
<artifactId>c3p0artifactId>
<version>0.9.5.3version>
dependency>
// 刚刚写的自动配置模块
<dependency>
<groupId>com.edugroupId>
<artifactId>c3p0-spring-boot-starter-autoconfigureartifactId>
<version>1.0-SNAPSHOTversion>
dependency>
dependencies>
project>
现在我们测试刚刚写的自动配置类能不能用上。创建个模块c3p0-spring-boot-sample,在创建个com包,在com包里面进行分层。
Info
@Data
public class Info {
private String name;
private Integer age;
private Date time;
}
InfoDao
public interface InfoDao {
List<Info> getAll(int pageNum, int pageSize);
}
InfoService
public interface InfoService {
List<Info> getAll(int pageNum, int pageSize);
}
InfoServiceImpl
@Service
public class InfoServiceImpl implements InfoService {
@Autowired
private InfoDao infoDao;
@Override
public List<Info> getAll(int pageNum, int pageSize) {
return infoDao.getAll(pageNum, pageSize);
}
}
InfoController
@Controller
public class InfoController {
@Autowired
private InfoService infoService;
@RequestMapping("/index")
@ResponseBody
public List<Info> index(){
return infoService.getAll(0, 2);
}
}
CustomStarterApp
@SpringBootApplication
@MapperScan("com.dao")
public class CustomStarterApp {
public static void main(String[] args) {
SpringApplication.run(CustomStarterApp.class, args);
}
}
InfoDao.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.dao.InfoDao">
<select id="getAll" resultType="info">
select * from info
</select>
</mapper>
application.yml
mybatis:
#对应实体类路径
type-aliases-package: com.entity
#对应mapper映射文件路径
mapper-locations: classpath:mapper/*.xml
# mybatis日志
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
c3p0:
driverClassname: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/demo?serverTimezone=GMT
username: root
password: root
pagehelper:
helper-dialect: mysql
support-methods-arguments: true
# 日期格式转换
spring:
jackson:
date-format: yyyy-MM-dd HH:mm:ss
time-zone: GMT+8
依赖
<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">
<parent>
<artifactId>custom-spring-start-parentartifactId>
<groupId>com.edugroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>c3p0-spring-boot-sampleartifactId>
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starterartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
<version>2.0.0version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
dependency>
<dependency>
<groupId>com.edugroupId>
<artifactId>c3p0-spring-boot-starterartifactId>
<version>1.0-SNAPSHOTversion>
dependency>
<dependency>
<groupId>com.github.pagehelpergroupId>
<artifactId>pagehelper-spring-boot-starterartifactId>
<version>1.2.10version>
dependency>
dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-maven-pluginartifactId>
plugin>
plugins>
build>
project>
结果:
到此c3p0连接池自动配置就已经配置完成了,如果你不想用c3p0,你可以把自动配置类理的dataSource类换成你自己想要的那个连接池即可。
网盘链接:https://pan.baidu.com/s/1UnNz8RHwyx0GvFXEITwI0w
提取码:fabu