Druid 是阿里巴巴开源平台上的一个项目,整个项目由数据库链接池、插件框架和 SQL 解析器组成。该项目主要是为了扩展 JDBC 的一些限制,可让程序员实现一些特殊的需求,好比向密钥服务请求凭证、统计 SQL 信息、SQL 性能收集、SQL 注入检查、SQL 翻译等,程序员能够经过定制来实现本身须要的功能。java
Druid 是目前最好的数据库链接池,在功能、性能、扩展性方面,都超过其余数据库链接池,包括 DBCP、C3P0、BoneCP、Proxool、JBoss DataSource。Druid 已经在阿里巴巴部署了超过 600 个应用,通过多年生产环境大规模部署的严苛考验。Druid 是阿里巴巴开发的号称为监控而生的数据库链接池!mysql
在 pom.xml 文件中引入 druid-spring-boot-starter 依赖git
<dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.20</version> </dependency>
引入数据库链接依赖程序员
<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency>
在 application.yml 中配置数据库链接github
spring: datasource: druid: url: jdbc:mysql://localhost:3306/gmall?useUnicode=true&characterEncoding=utf-8&useSSL=false username: root password: 3662402 initial-size: 1 min-idle: 1 max-active: 20 test-on-borrow: true # MySQL 8.x: com.mysql.cj.jdbc.Driver driver-class-name: com.mysql.jdbc.Driver mybatis: type-aliases-package: com.bao.spring.boot.mybatis.entity mapper-locations: classpath:mapper/*.xml
tk.mybatis 是在 MyBatis 框架的基础上提供了不少工具,让开发更加高效web
在 pom.xml 文件中引入 mapper-spring-boot-starter 依赖,该依赖会自动引入 MyBaits 相关依赖spring
<dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper-spring-boot-starter</artifactId> <version>2.1.5</version> </dependency>
配置 MyBatissql
mybatis: type-aliases-package: 实体类的存放路径,如:com.hello.spring.boot.entity mapper-locations: classpath:mapper/*.xml
主要做用是让 DAO 层的接口继承该接口,以达到使用 tk.mybatis 的目的数据库
特别注意,该接口不能被扫描到(例如:不能被spring扫描到),不然会出错,出错缘由,apache
与spring集成的原生mybatis注解有冲突
package tk.mybatis; import tk.mybatis.mapper.common.Mapper; import tk.mybatis.mapper.common.MySqlMapper; /** * 本身的 Mapper * 特别注意,该接口不能被扫描到(例如:不能被spring扫描到),不然会出错 */ public interface MyMapper<T> extends Mapper<T>, MySqlMapper<T> { }
咱们无需手动编写 实体类、DAO、XML 配置文件,只须要使用 MyBatis 提供的一个 Maven 插件就能够自动生成所需的各类文件便可以知足基本的业务需求,若是业务比较复杂只须要修改相关文件便可。
在 pom.xml
文件中增长 mybatis-generator-maven-plugin
插件
<build> <plugins> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.7</version> <configuration> <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile> <overwrite>true</overwrite> <verbose>true</verbose> </configuration> <dependencies> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper</artifactId> <version>4.1.5</version> </dependency> </dependencies> </plugin> </plugins> </build>
注意:
configurationFile
自动生成所需的配置文件路径
在 src/main/resources/generator/
目录下建立 generatorConfig.xml
配置文件:
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"> <generatorConfiguration> <!-- 引入数据库链接配置 --> <properties resource="jdbc.properties"/> <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat"> <property name="beginningDelimiter" value="`"/> <property name="endingDelimiter" value="`"/> <!-- 配置 tk.mybatis 插件 --> <plugin type="tk.mybatis.mapper.generator.MapperPlugin"> <property name="mappers" value="tk.mybatis.MyMapper"/> </plugin> <!-- 配置数据库链接 --> <jdbcConnection driverClass="${jdbc.driverClass}" connectionURL="${jdbc.connectionURL}" userId="${jdbc.username}" password="${jdbc.password}"> </jdbcConnection> <!-- 配置实体类存放路径 --> <javaModelGenerator targetPackage="com.bao.spring.boot.mybatis.entity" targetProject="src/main/java"/> <!-- 配置 XML 存放路径 --> <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources"/> <!-- 配置 DAO 存放路径 --> <javaClientGenerator targetPackage="com.bao.spring.boot.mybatis.mapper" targetProject="src/main/java" type="XMLMAPPER"/> <!-- 配置须要指定生成的数据库和表,% 表明全部表 --> <table catalog="myshop" tableName="%"> <!-- 默认为 false,若是设置为 true,在生成的 SQL 中,table 名字不会加上 catalog 或 schema --> <property name="ignoreQualifiersAtRuntime" value="true"/> <!-- mysql 配置 --> <generatedKey column="id" sqlStatement="Mysql" identity="true"/> </table> </context> </generatorConfiguration>
在 src/main/resources
目录下建立 jdbc.properties
数据源配置:
jdbc.driverClass=com.mysql.cj.jdbc.Driver jdbc.connectionURL=jdbc:mysql://localhost:3306/myshop?useUnicode=true&characterEncoding=utf-8&useSSL=false jdbc.username=root jdbc.password=3662402
若有时区错误,使用下面的这个代码
jdbc.driverClass=com.mysql.jdbc.Driver jdbc.connectionURL=jdbc:mysql://localhost:3306/myshop?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf-8&useSSL=false jdbc.username=root jdbc.password=3662402
完整的pom文件
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.8.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.bao</groupId> <artifactId>springboot-mybatis</artifactId> <version>0.0.1-SNAPSHOT</version> <name>springboot-mybatis</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <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.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.20</version> </dependency> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper-spring-boot-starter</artifactId> <version>2.1.5</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper-spring-boot-starter</artifactId> <version>1.2.12</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>1.3.7</version> <configuration> <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile> <overwrite>true</overwrite> <verbose>true</verbose> </configuration> <dependencies> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <dependency> <groupId>tk.mybatis</groupId> <artifactId>mapper</artifactId> <version>4.1.5</version> </dependency> </dependencies> </plugin> </plugins> </build> </project>
项目结构目录