WEB工程中使用 mybatis 和 Druid 连接池非常多，这里简单介绍一下在springboot 2.0中的使用例子，使用的MS SQL Server 2008数据库，工程项目的准备工作；工程样本建立；工程导入Eclipse开发环境，下载相关依赖JAR包步骤参考前一篇博文，这里省略，仅仅展示关键之处，整个工程结构如下图，
一，工程 pom.xml 修改，引入druid数据库链接池和相应数据库对应的依赖jar包，内容如下，
<?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.qyh</groupId>
<artifactId>springBoot01Database</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springBoot01Database</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<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>
<!-- ms sql server JDBC 依赖jar包 -->
<dependency>
<groupId>com.microsoft.sqlserver</groupId>
<artifactId>mssql-jdbc</artifactId>
<scope>runtime</scope>
</dependency>
<!-- mysql db 依赖jar包 -->
<!--
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
-->
<!-- oracle db 依赖jar包,好像难从maven仓库下载,需手动下载放到本地仓库 -->
<!--
<dependency>
<groupId>com.oracle</groupId>
<artifactId>ojdbc6</artifactId>
<version>11.2.0.2.0</version>
</dependency>
-->
<!-- start:使用druid数据源依赖 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.2</version>
</dependency>
<!-- end:使用druid数据源依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- 支持热部署依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<defaultGoal>compile</defaultGoal>
<finalName>springBoot01Database</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<!-- 没有该配置，devtools 不生效 -->
<fork>true</fork>
</configuration>
</plugin>
</plugins>
</build>
</project>
为方便在开发，测试，生成三种环境之间切换，配置文件分为三个，即： application-dev.properties，application-test.properties，application-prod.properties，然后 application.properties 仅仅配置一行使用其中一种环境即可， springboot启动读取的是 application.properties 配置文件，需要注意的是， mybatis 指定的实体包，本地是配置XML文件和数据库表到实体的映射XML文件需要在配置文件中指定，如下为各个配置文件，
#===================================================
# application-dev.properties
#===================================================
# server evn setting
#===================================================
server.address=127.0.0.1
server.port=8080
server.servlet.contextPath=/
server.session-timeout=30
#=====For springMVC setting=====
spring.thymeleaf.prefix=classpath:/templates/
#spring.thymeleaf.suffix=.html
spring.mvc.view.prefix=/WEB-INF/view/
spring.mvc.view.suffix=.jsp
#===================================================
# database setting
#===================================================
#=====For connect ms sql server use jdbc pool=====
#use dependency: jdbc[default] and mybatis-spring-boot-starter-1.1.1.jar
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driverClassName=com.microsoft.sqlserver.jdbc.SQLServerDriver
spring.datasource.url=jdbc:sqlserver://localhost:1433;databaseName=myDBName
spring.datasource.username=dbUserName
spring.datasource.password=dbPassword
#=====For connect mysql use jdbc pool=====
#spring.datasource.driverClassName=com.mysql.jdbc.Driver
#spring.datasource.url=jdbc:mysql://127.0.0.1:3306/myDBName?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8
#spring.datasource.username=DBUserName
#spring.datasource.password=DBPassword
#=====For connect oracle db use jdbc pool=====
#spring.datasource.driverClassName=oracle.jdbc.OracleDriver
#spring.datasource.url=jdbc:oracle:thin:@localhost:1521:oracleSID
#spring.datasource.username=DBUserName
#spring.datasource.password=DBPassword
#=====For common dataSource setting info=====
spring.datasource.initialSize=10
spring.datasource.minIdle=10
spring.datasource.maxActive=120
spring.datasource.maxWait=60000
spring.datasource.timeBetweenEvictionRunsMillis=60000
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=SELECT 1
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false
spring.datasource.poolPreparedStatements=true
spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
spring.datasource.filters=stat,wall
#spring.datasource.filters=stat,wall,log4j
spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
#=====For mybatis setting======
mybatis.typeAliasesPackage=com.qyh.pro01.model,com.qyh.pro01.param
mybatis.configLocations=classpath:config/mybatisConfig.xml
#main thing is setting alias, can not use configLocations
mybatis.mapperLocations=classpath:mapper/*.xml
#===================================================
# other setting
#===================================================
#===================================================
#application.properties
#===================================================
spring.profiles.active=dev
#active dev evn
mybatis的本地配置文件主要是定义实体的别名，同时还有数据库连接的一些基本信息（可以不设置）， 整个文件可以不用，为完整这里使用，代码如下，
<?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 部分可以不用 -->
<!--
<settings>
<setting name="cacheEnabled" value="true" />
<setting name="lazyLoadingEnabled" value="true" />
<setting name="aggressiveLazyLoading" value="true"/>
<setting name="multipleResultSetsEnabled" value="true"/>
<setting name="useColumnLabel" value="true" />
<setting name="defaultExecutorType" value="SIMPLE" />
<setting name="defaultStatementTimeout" value="60000"/>
</settings>
-->
<!-- can more setting add here -->
<!-- POJO的别名设置 -->
<typeAliases>
<typeAlias alias="member" type="com.qyh.pro01.model.Member" />
</typeAliases>
<!-- 当单独使用mybatis时设置,此处为链接 MS SQL SERVER 2008 -->
<!--
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver"/>
<property name="url" value="jdbc:sqlserver://localhost:1433;databaseName=myDBName" />
<property name="username" value="dbUserName"/>
<property name="password" value="dbPassword"/>
</dataSource>
</environment>
</environments>
-->
<!-- 当单独使用mybatis时设置映射XML文件 -->
<!--
<mappers>
<mapper resource="mapper/Member.xml"/>
</mappers>
-->
</configuration>
此外还有库表到JAVA实体对应的各个映射mapper的XML文件，此处省略。
四，编写自定义数据源类，目的是产生DataSource和SqlSessionFactory并注入spring容器中，类正确使用相应注解，并确保其所在的包在启动类中扫描到，代码如下，
package com.qyh.pro01.common;
import java.sql.SQLException;
import javax.sql.DataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.env.Environment;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import com.alibaba.druid.pool.DruidDataSource;
/**
* @author shenzhenNBA
* @since 2018.06.10
* 自定义数据源类
*/
@Configuration //该注解类似于spring配置文件
public class MyDataSourceConfig {
private Logger logger = LoggerFactory.getLogger(MyDataSourceConfig.class);
@Autowired
private Environment env;
//使用该实例读取项目资源路径下application.properties文件中的内容
@Value("${spring.datasource.type}") //读取配置文件中指定KEY的值到变量中
private String dbType;
@Value("${spring.datasource.url}")
private String dbUrl;
@Value("${spring.datasource.username}")
private String username;
@Value("${spring.datasource.password}")
private String password;
@Value("${spring.datasource.driverClassName}")
private String driverClassName;
@Value("${spring.datasource.initialSize}")
private int initialSize;
@Value("${spring.datasource.minIdle}")
private int minIdle;
@Value("${spring.datasource.maxActive}")
private int maxActive;
@Value("${spring.datasource.maxWait}")
private int maxWait;
@Value("${spring.datasource.timeBetweenEvictionRunsMillis}")
private int timeBetweenEvictionRunsMillis;
@Value("${spring.datasource.minEvictableIdleTimeMillis}")
private int minEvictableIdleTimeMillis;
@Value("${spring.datasource.validationQuery}")
private String validationQuery;
@Value("${spring.datasource.testWhileIdle}")
private boolean testWhileIdle;
@Value("${spring.datasource.testOnBorrow}")
private boolean testOnBorrow;
@Value("${spring.datasource.testOnReturn}")
private boolean testOnReturn;
@Value("${spring.datasource.poolPreparedStatements}")
private boolean poolPreparedStatements;
@Value("${spring.datasource.maxPoolPreparedStatementPerConnectionSize}")
private int maxPoolPreparedStatementPerConnectionSize;
@Value("${spring.datasource.filters}")
private String filters;
@Value("{spring.datasource.connectionProperties}")
private String connectionProperties;
@Bean //产生bean实例加载进srping容器中,与spring配置文件中配置bean一样
@Primary //当有多个实现时以此为优先为准
public DataSource getDataSource() throws Exception{
DruidDataSource datasource = new DruidDataSource();
//datasource.setDbType(dbType); //有些版本不支持该属性
datasource.setUrl(dbUrl);
//datasource.setUrl(env.getProperty("spring.datasource.url"));
//使用Environment对象实例读取property文件中指定key的值,配置文件读取方式之一
datasource.setDriverClassName(driverClassName);
datasource.setUsername(username);
datasource.setPassword(password);
//configuration
datasource.setInitialSize(initialSize);
datasource.setMinIdle(minIdle);
datasource.setMaxActive(maxActive);
datasource.setMaxWait(maxWait);
datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
datasource.setValidationQuery(validationQuery);
datasource.setTestWhileIdle(testWhileIdle);
datasource.setTestOnBorrow(testOnBorrow);
datasource.setTestOnReturn(testOnReturn);
datasource.setPoolPreparedStatements(poolPreparedStatements);
datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
try {
datasource.setFilters(filters);
} catch (SQLException e) {
logger.error("druid configuration initialization filter", e);
}
datasource.setConnectionProperties(connectionProperties);
return datasource;
}
@Bean //产生bean实例加载进srping容器中,与spring配置文件中配置bean一样
public SqlSessionFactory sqlSessionFactory(DataSource ds) throws Exception{
SqlSessionFactoryBean sqlSFB = new SqlSessionFactoryBean();
sqlSFB.setDataSource(ds);
//指定自定义的数据源,这个必须用,否则报错
sqlSFB.setTypeAliasesPackage(env.getProperty("mybatis.typeAliasesPackage"));
//指定对应的实体包,多个包之间逗号隔开
Resource configLocationResource = new PathMatchingResourcePatternResolver().getResource(
env.getProperty("mybatis.configLocations"));
sqlSFB.setConfigLocation(configLocationResource);
//指定mybatis的本地配置文件资源,目的是定义实体等别名,可以不用,如果不用对应配置文件应注释掉
Resource[] mapperLocations = new PathMatchingResourcePatternResolver().getResources(
env.getProperty("mybatis.mapperLocations"));
sqlSFB.setMapperLocations(mapperLocations);
//指定mybatis的库表到实体的映射xml文件的mapper资源
return sqlSFB.getObject();
}
}
因为要使用 Druid 和 mybatis 对数据库进行操作， 所以必须在启动类中使用相应的注解并扫描各个相应的包，然后目标包中的各个含有各种注解的类对应的实例才能加载进spring容器中，才能使用；比如使用 @EntityScan扫描实体对应所在的包， @MapperScan扫描DAO层定义的接口所在的包， @ComponentScan扫描controller，service等所在的包，如下为启动类代码，
package com.qyh.springBootApp;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.context.annotation.ComponentScan;
/**
* springboot+mybatis+druid+mssqlserver例子
* @author shenzhenNBA
* @since 2018.06.10
*/
@SpringBootApplication //标注为启动类
@EntityScan("com.qyh.pro01.model,com.qyh.pro01.param") //扫描实体所在的包
@MapperScan("com.qyh.pro01.dao") //扫描DAO接口所在的包
@ComponentScan("com.qyh.pro01.common" //扫描自定义数据源所在的包
+ ",com.qyh.pro01.controller" //扫描控制器所在的包
+ ",com.qyh.pro01.service.impl") //扫描业务接口实现类所在的包
public class SpringBoot01DBApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBoot01DBApplication.class, args);
}
}
当项目启动后，对数据库进行操作时即可看到 Druid 已经进行了初始化，如下图所示，
以上设置完即可在项目中使用 Druid 数据源连接池了，总的来说要使用 Druid ，首先需要引入 Druid 依赖JAR包和对应各种数据库的依赖JAR包，其次在properties配置文件中设置对应的数据源信息，然后编写mybatis对应本地配置XML文件（主要定义实体别名，这个不是必须），再然后编写自定义的数据源类，最后在启动类中扫描到自定义数据源的类，这样即可使用 druid 数据源了， 此为俺做的例子，欢迎拍砖讨论....