[Java知识库]SpringBoot+druid Mysql连接池使用

零、Mybatis与Mysql连接池使用

一、代码

1、POM依赖

implementation 'org.springframework.boot:spring-boot-starter-web'
implementation 'org.mybatis.spring.boot:mybatis-spring-boot-starter:2.1.4'
implementation group: 'mysql', name: 'mysql-connector-java', version: '8.0.25'
compile group: 'com.alibaba', name: 'druid', version: '1.2.4'

2、application.properties配置数据库

#数据库
jdbc.driverClassName=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://1.2.3.4:3306/TestDBMysql?allowMultiQueries=true
jdbc.username=admin
jdbc.password=123456
jdbc.maxActive=10
jdbc.maxIdle=10
jdbc.minIdle=2

druid配置文件 resources/applicationContext.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"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">


    <context:property-placeholder location="classpath*:*.properties"/>

    <context:component-scan base-package="com.longze">

    </context:component-scan>

<!--    <context:component-scan base-package="springfox.documentation" use-default-filters="true">-->

<!--    </context:component-scan>-->


    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="redirectHttp10Compatible" value="false" />
    </bean>


    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
          destroy-method="close">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>

        <!-- 数据池中最大连接数和最小连接数-->
        <property name="maxActive" value="${jdbc.maxActive}"/>
        <property name="minIdle" value="${jdbc.minIdle}"/>
    </bean>

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 注入连接池
         给 sqlsessionFactory 的属性 dataSource 赋值
            ref="引用该 spring容器 中的另一个 bean的id"
        -->
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <!-- 注入 映射文件 mapper
         给 sqlsessionFactory 的属性 mapperLocation 赋值
           value="映射文件 XXXmapper.xml 的相对路径"
          -->
        <property name="mapperLocations" value="classpath:mappers/*.xml"/>
    </bean>

    <!-- 3) 获取 SqlSession 对象，并交由 spring 管理  用SqlSessionTemplate得到的SqlSession可以不用我们自己操心事务的管理，以及关闭操作-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!-- 给 SqlSessionTemplate 的构造函数赋值-->
        <constructor-arg index="0" ref="sqlSessionFactory" />
    </bean>

</beans>

Mybatis的配置文件resources/mybatis-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>
    <settings>
<!--        STDOUT_LOGGING-->
<!--        <setting name="logImpl" value="LOG4J2" />-->

<!--         <setting name="logImpl" value="STDOUT_LOGGING" />-->

        <setting name="callSettersOnNulls" value="true"/>
        <setting name="jdbcTypeForNull" value="NULL" />
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>

    <!--配置分页插件-->
<!--    <plugins>-->
<!--        <plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>-->
<!--    </plugins>-->


</configuration>

3、MainApplication.java启动类配置

@SpringBootApplication
@ImportResource({"classpath:applicationContext.xml"})
public class SecurityApplication {
    public static void main(String[] args) {SpringApplication.run(SecurityApplication.class, args);}
}

4、Mybatis线程池工具类

com.longze.util.MyBatisUtil.java

package com.longze.security.util;

import org.apache.ibatis.session.SqlSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.context.WebApplicationContext;

@Component
public class MyBatisUtil {
    private static WebApplicationContext context;
    public static WebApplicationContext getContext() {
        return context;
    }
    @Autowired
    public void setContext(WebApplicationContext context) {
        setContextStatic(context);
    }
    public static SqlSession getSqlSession() {
        return (SqlSession) context.getBean("sqlSession");
    }
    public static void setContextStatic(WebApplicationContext context){
        MyBatisUtil.context=context;
    }
}

5、使用线程池工具类

@Service
public class MyBatisTestServiceImpl implements MyBatisTestService{
 @Override
    public int save(UserDTO dto){
        try {
            //使用线程池
            int i = MyBatisUtil.getSqlSession().insert("com.longze.dao.testDao.insertUser", dto);
            return i;
        } catch (Exception e) {
            throw  e;
        }
    }

}

二、多数据源应用