Druid 是阿里巴巴開源平臺上的一個項目,整個項目由數據庫鏈接池、插件框架和 SQL 解析器組成。該項目主要是爲了擴展 JDBC 的一些限制,可讓程序員實現一些特殊的需求,好比向密鑰服務請求憑證、統計 SQL 信息、SQL 性能收集、SQL 注入檢查、SQL 翻譯等,程序員能夠經過定製來實現本身須要的功能。java
Druid 是目前最好的數據庫鏈接池,在功能、性能、擴展性方面,都超過其餘數據庫鏈接池,包括 DBCP、C3P0、BoneCP、Proxool、JBoss DataSource。Druid 已經在阿里巴巴部署了超過 600 個應用,通過多年生產環境大規模部署的嚴苛考驗。Druid 是阿里巴巴開發的號稱爲監控而生的數據庫鏈接池!mysql
在 pom.xml 文件中引入 druid-spring-boot-starter 依賴git
<dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.20</version> </dependency>
引入數據庫鏈接依賴程序員
<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency>
在 application.yml 中配置數據庫鏈接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 框架的基礎上提供了不少工具,讓開發更加高效web
在 pom.xml 文件中引入 mapper-spring-boot-starter 依賴,該依賴會自動引入 MyBaits 相關依賴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: 實體類的存放路徑,如:com.hello.spring.boot.entity mapper-locations: classpath:mapper/*.xml
主要做用是讓 DAO 層的接口繼承該接口,以達到使用 tk.mybatis 的目的數據庫
特別注意,該接口不能被掃描到(例如:不能被spring掃描到),不然會出錯,出錯緣由,apache
與spring集成的原生mybatis註解有衝突
package tk.mybatis; import tk.mybatis.mapper.common.Mapper; import tk.mybatis.mapper.common.MySqlMapper; /** * 本身的 Mapper * 特別注意,該接口不能被掃描到(例如:不能被spring掃描到),不然會出錯 */ public interface MyMapper<T> extends Mapper<T>, MySqlMapper<T> { }
咱們無需手動編寫 實體類、DAO、XML 配置文件,只須要使用 MyBatis 提供的一個 Maven 插件就能夠自動生成所需的各類文件便可以知足基本的業務需求,若是業務比較複雜只須要修改相關文件便可。
在 pom.xml
文件中增長 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
自動生成所需的配置文件路徑
在 src/main/resources/generator/
目錄下建立 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> <!-- 引入數據庫鏈接配置 --> <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> <!-- 配置數據庫鏈接 --> <jdbcConnection driverClass="${jdbc.driverClass}" connectionURL="${jdbc.connectionURL}" userId="${jdbc.username}" password="${jdbc.password}"> </jdbcConnection> <!-- 配置實體類存放路徑 --> <javaModelGenerator targetPackage="com.bao.spring.boot.mybatis.entity" targetProject="src/main/java"/> <!-- 配置 XML 存放路徑 --> <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources"/> <!-- 配置 DAO 存放路徑 --> <javaClientGenerator targetPackage="com.bao.spring.boot.mybatis.mapper" targetProject="src/main/java" type="XMLMAPPER"/> <!-- 配置須要指定生成的數據庫和表,% 表明全部表 --> <table catalog="myshop" tableName="%"> <!-- 默認爲 false,若是設置爲 true,在生成的 SQL 中,table 名字不會加上 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
目錄下建立 jdbc.properties
數據源配置:
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
若有時區錯誤,使用下面的這個代碼
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>
項目結構目錄