spring boot连接mysql数据库

一、现在大部分持久化层ORM实现框架用的都是mybatis,spring Boot开始使用之后,mybatis官网也发布了mybatis-spring-boot-starter包来支持springboot集成开发,在jdbc连接数据库的spring-boot-starter-jdbc包中,mybatis默认选择了引入第三方数据库连接池工具HiKariCp

这样做应该是考虑到Hikari是目前公认的连接性能最强的连接池工具。

二、如果不单单考虑性能,按综合能力考量 ,阿里的Druid其实是功能最强大的数据库连接池工具。当然,阿里也为我们提供了支持springboot开发的starter包Druid-spring-boot-starter。

我个人比较偏向集成Druid做数据库连接池工作,虽然需要单独引入Druid的starter包,但是他的监控功能确实做的很好。

三、下面来具体分析下

1、首先分析下Hikari和Druid

参考博文 :https://blog.csdn.net/qq_17085463/article/details/90486515

总结来说,Hikari速度快,Druid功能强

2、具体使用:

参考博文:https://blog.csdn.net/weixin_38187317/article/details/81562571

github路径:mybatis-spring-boot-starter    https://github.com/mybatis/spring-boot-starter

      Druid-spring-boot-starter       https://github.com/alibaba/druid/tree/master/druid-spring-boot-starter

       关于Druid的中文说明:https://github.com/alibaba/druid/wiki/%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98

如果使用mybatis的默认连接池Hikari,只需要引入pom依赖和配置application.properties文件如下:

#spring.datasource.driver-class-name:com.mysql.cj.jdbc.Driver
#mybaits扫描设置
mybatis.config-location=classpath:config/mybatis-config.xml
mybatis.mapper-locations=classpath*:dbmapper/*.xml
# 解析结果集对应的model路径,当然,如果在mapper.xml中写全限定名就不用配置这里
#  mybatis.type-aliases-package=com.example.mybatisdemo.db.model
# mybatis.configuration.mapped-statements=com.example.mybatisdemo.db.dao

#数据连接设置
spring.datasource.url:jdbc:mysql://192.*.100.29:3306/testdb?useUnicode=true&characterEncoding=utf-8
spring.datasource.username:root
spring.datasource.password:root
<properties>
        <java.version>1.8</java.version>
        <plugin.mybatis.generator>1.3.1</plugin.mybatis.generator>
</properties>
<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
</dependencies>
<build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>${plugin.mybatis.generator}</version>
                <configuration>
                    <configurationFile>src/main/resources/config/generatorConfig.xml</configurationFile>
                    <overwrite>true</overwrite>
                    <verbose>true</verbose>
                </configuration>
            </plugin>
        </plugins>
    </build>

如果使用mybatis外接连接池Druid,则需要配置如下:

#spring.datasource.driver-class-name:com.mysql.cj.jdbc.Driver
#mybaits扫描设置
mybatis.config-location=classpath:config/mybatis-config.xml
mybatis.mapper-locations=classpath*:dbmapper/*.xml


#数据连接设置
server.port=8080

spring.application.name=springboot-test-exam1

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url:jdbc:mysql://192.*.*.29:3306/testdb?useUnicode=true&characterEncoding=utf-8
spring.datasource.username:root
spring.datasource.password:root
spring.datasource.druid.initial-size=5
spring.datasource.druid.min-idle=5
spring.datasource.druid.maxActive=20
spring.datasource.druid.maxWait=60000
spring.datasource.druid.timeBetweenEvictionRunsMillis=60000
spring.datasource.druid.minEvictableIdleTimeMillis=300000
spring.datasource.druid.validationQuery=SELECT 1 FROM DUAL
spring.datasource.druid.testWhileIdle=true
spring.datasource.druid.testOnBorrow=false
spring.datasource.druid.testOnReturn=false
spring.datasource.druid.poolPreparedStatements=true
spring.datasource.druid.maxPoolPreparedStatementPerConnectionSize=20
spring.datasource.druid.filters=stat,wall,slf4j
spring.datasource.druid.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
spring.datasource.druid.web-stat-filter.enabled=true
spring.datasource.druid.web-stat-filter.url-pattern=/*
spring.datasource.druid.web-stat-filter.exclusions=*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*
spring.datasource.druid.stat-view-servlet.enabled=true
spring.datasource.druid.stat-view-servlet.url-pattern=/druid/*
spring.datasource.druid.stat-view-servlet.allow=127.0.0.1,192.168.163.1
spring.datasource.druid.stat-view-servlet.deny=192.168.1.73
spring.datasource.druid.stat-view-servlet.reset-enable=false
spring.datasource.druid.stat-view-servlet.login-username=admin
spring.datasource.druid.stat-view-servlet.login-password=123456
Druid配置
<properties>
        <java.version>1.8</java.version>
        <plugin.mybatis.generator>1.3.1</plugin.mybatis.generator>
</properties>
<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
 <!-- DruidDataSource -->

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.10</version>
        </dependency>
</dependencies>
<build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>${plugin.mybatis.generator}</version>
                <configuration>
                    <configurationFile>src/main/resources/config/generatorConfig.xml</configurationFile>
                    <overwrite>true</overwrite>
                    <verbose>true</verbose>
                </configuration>
            </plugin>
        </plugins>
    </build>

Druid监控信息访问路径:http://localhost:8080/druid/

3、源码底层分析

通过配置错误的数据库连接信息会发现

1)、项目启动过程中,Druid在初始化Datasource时会对数据库进行测试连接而Hikari并没有。

2)、两者都是在解析完sql之后进行的数据库连接,如果解析错误,则不进行数据库连接。

我写的一篇浅跟mybaits中使用的连接池就是Druid

下面在来简单看看Hikari的源码跟踪: