SpringCloud微服務實戰——搭建企業級開發框架（五）：數據庫持久化集成MySql+Druid+MyBatis-Plus

  在引入相關數據庫持久化相關依賴庫之前，我們可以考慮到，當我們因業務開發需要，引入各種各樣的依賴庫時，Jar包沖突是我們必須面對的一個問題，Spring為了解決這些Jar包的沖突，推出了各種bom，最著名的就是Spring IO Platform bom，其中最核心的三個是：spring-framework-bom、spring-boot-dependencies、platform-bom。我們這里參考Spring管理Jar包的方式，新建一個GitEgg-Platform平台工程，提供各種第三方組件的配置及自定義方法，使用子工程gitegg-platform-bom統一管理GitEgg自定義方法擴展jar包及第三方Jar包版本。
1、首先在GitEgg-Platform工程下新建gitegg-platform-db用於管理系統需要用到的數據庫驅動、數據庫連接池的jar包及配置，新建gitegg-platform-mybatis用於管理系統需要用到的持久層框架，建好的結構如下：

2、修改GitEgg-Platform根目錄下的pom.xml，設置工程編碼方式，及引入的Spring Boot，Spring Cloud，gitegg-platform-bom版本：

<!--?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.gitegg.platform</groupid>
    <artifactid>GitEgg-Platform</artifactid>
    <name>${project.artifactId}</name>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>

    <modules>
        <module>gitegg-platform-bom</module>
        <module>gitegg-platform-db</module>
        <module>gitegg-platform-mybatis</module>
    </modules>

    <properties>
        <!-- jdk版本1.8 -->
        <java.version>1.8</java.version>
        <!-- maven-compiler-plugin插件版本，Java代碼編譯 -->
        <maven.plugin.version>3.8.1</maven.plugin.version>
        <!-- maven編譯時指定編碼UTF-8 -->
        <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
        <!-- 項目統一字符集編碼UTF-8 -->
        <project.build.sourceencoding>UTF-8</project.build.sourceencoding>
        <!-- 項目統一字符集編碼UTF-8 -->
        <project.reporting.outputencoding>UTF-8</project.reporting.outputencoding>

        <!-- SpringBoot版本號 -->
        <spring.boot.version>2.3.3.RELEASE</spring.boot.version>
        <!-- SpringCloud版本號 -->
        <spring.cloud.version>Hoxton.SR8</spring.cloud.version>
        <!-- SpringPlatform版本號 -->
        <spring.platform.version>Cairo-SR8</spring.platform.version>

    </properties>

    <dependencymanagement>
        <dependencies>
            <dependency>
                <groupid>com.gitegg.platform</groupid>
                <artifactid>gitegg-platform-bom</artifactid>
                <version>${project.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupid>org.springframework.boot</groupid>
                <artifactid>spring-boot-dependencies</artifactid>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupid>org.springframework.cloud</groupid>
                <artifactid>spring-cloud-dependencies</artifactid>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencymanagement>

    <build>
        <finalname>${project.name}</finalname>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
        </resources>
        <plugins>
            <plugin>
                <groupid>org.apache.maven.plugins</groupid>
                <artifactid>maven-compiler-plugin</artifactid>
                <version>${maven.plugin.version}</version>
                <configuration>
                    <source>${java.version}
                    <target>${java.version}</target>
                    <encoding>UTF-8</encoding>
                    <compilerargs>
                        <arg>-parameters</arg>
                    </compilerargs>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>aliyun-repos</id>
            <url>https://maven.aliyun.com/nexus/content/groups/public/</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
        <repository>
            <id>gitegg-release</id>
            <name>Release Repository</name>
            <url>https://packages.aliyun.com/maven/repository/2020515-release-dpxo1j/</url>
        </repository>
    </repositories>

    <pluginrepositories>
        <pluginrepository>
            <id>aliyun-plugin</id>
            <url>https://maven.aliyun.com/nexus/content/groups/public/</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </pluginrepository>
    </pluginrepositories>

    <profiles>
        <profile>
            <id>dev</id>
            <properties>
                <profileactive>dev</profileactive>
            </properties>
            <activation>
                <!--默認為dev環境打包方式-->
                <activebydefault>true</activebydefault>
            </activation>
        </profile>
        <profile>
            <id>test</id>
            <properties>
                <profileactive>test</profileactive>
            </properties>
        </profile>
        <profile>
            <id>pro</id>
            <properties>
                <profileactive>pro</profileactive>
            </properties>
        </profile>
    </profiles>

</project>

3、修改gitegg-platform-bom工程下的pom.xml，引入目前需要的數據庫驅動，數據連接池及Mybatis-Plus：

<!--?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">

    <parent>
        <groupid>org.springframework.boot</groupid>
        <artifactid>spring-boot-starter-parent</artifactid>
        <version>2.3.3.RELEASE</version>
        <relativepath>
    </relativepath></parent>

    <modelversion>4.0.0</modelversion>

    <groupid>com.gitegg.platform</groupid>
    <artifactid>gitegg-platform-bom</artifactid>
    <name>${project.artifactId}</name>
    <version>${gitegg.project.version}</version>
    <packaging>pom</packaging>

    <properties>
        <!-- jdk版本1.8 -->
        <java.version>1.8</java.version>
        <!-- maven-compiler-plugin插件版本，Java代碼編譯 -->
        <maven.plugin.version>3.8.1</maven.plugin.version>
        <!-- maven編譯時指定編碼UTF-8 -->
        <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
        <!-- 項目統一字符集編碼UTF-8 -->
        <project.build.sourceencoding>UTF-8</project.build.sourceencoding>
        <!-- 項目統一字符集編碼UTF-8 -->
        <project.reporting.outputencoding>UTF-8</project.reporting.outputencoding>

        <!-- GitEgg項目統一設置版本號 -->
        <gitegg.project.version>1.0-SNAPSHOT</gitegg.project.version>

        <!-- mysql數據庫驅動 -->
        <mysql.connector.version>8.0.17</mysql.connector.version>
        <!-- postgresql數據庫驅動 -->
        <postgresql.connector.version>9.1-901.jdbc4</postgresql.connector.version>
        <!-- 數據庫連接池Druid -->
        <druid.version>1.1.23</druid.version>
        <!-- Mybatis Plus增強工具 -->
        <mybatis.plus.version>3.4.0</mybatis.plus.version>

    </properties>

    <dependencymanagement>
        <dependencies>
            <!-- gitegg數據庫驅動及連接池 -->
            <dependency>
                <groupid>com.gitegg.platform</groupid>
                <artifactid>gitegg-platform-db</artifactid>
                <version>${gitegg.project.version}</version>
            </dependency>
            <!-- gitegg mybatis-plus -->
            <dependency>
                <groupid>com.gitegg.platform</groupid>
                <artifactid>gitegg-platform-mybatis</artifactid>
                <version>${gitegg.project.version}</version>
            </dependency>
            <!-- mysql數據庫驅動 -->
            <dependency>
                <groupid>mysql</groupid>
                <artifactid>mysql-connector-java</artifactid>
                <version>${mysql.connector.version}</version>
            </dependency>
            <!-- postgresql數據庫驅動 -->
            <dependency>
                <groupid>postgresql</groupid>
                <artifactid>postgresql</artifactid>
                <version>${postgresql.connector.version}</version>
            </dependency>
            <!-- 數據庫連接池 -->
            <dependency>
                <groupid>com.alibaba</groupid>
                <artifactid>druid-spring-boot-starter</artifactid>
                <version>${druid.version}</version>
            </dependency>
            <!-- Mybatis Plus增強工具 -->
            <dependency>
                <groupid>com.baomidou</groupid>
                <artifactid>mybatis-plus-boot-starter</artifactid>
                <version>${mybatis.plus.version}</version>
            </dependency>
        </dependencies>
    </dependencymanagement>


</project>

4、修改gitegg-platform-db工程下的pom.xml，只引入數據庫驅動及數據庫連接池相關jar包：

<!--?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">
    <parent>
        <artifactid>GitEgg-Platform</artifactid>
        <groupid>com.gitegg.platform</groupid>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelversion>4.0.0</modelversion>

    <artifactid>gitegg-platform-db</artifactid>
    <name>${project.artifactId}</name>
    <version>${project.parent.version}</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupid>mysql</groupid>
            <artifactid>mysql-connector-java</artifactid>
        </dependency>
        <dependency>
            <groupid>postgresql</groupid>
            <artifactid>postgresql</artifactid>
        </dependency>
        <dependency>
            <groupid>com.alibaba</groupid>
            <artifactid>druid-spring-boot-starter</artifactid>
        </dependency>
    </dependencies>
</project>

5、修改gitegg-platform-mybatis工程下的pom.xml，只引入mybatis-plus相關jar包：

<!--?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">
    <parent>
        <artifactid>GitEgg-Platform</artifactid>
        <groupid>com.gitegg.platform</groupid>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelversion>4.0.0</modelversion>

    <artifactid>gitegg-platform-mybatis</artifactid>
    <name>${project.artifactId}</name>
    <version>${project.parent.version}</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupid>com.baomidou</groupid>
            <artifactid>mybatis-plus-boot-starter</artifactid>
        </dependency>
    </dependencies>

</project>

6、pom.xml文件配置好之后，在IDEA右側窗口，Maven中點擊install，將包安裝到本地，這樣GitEgg-Cloud工程就可以引用GitEgg-Platform工程的jar包了，同理，測試及正式環境需要點擊deploy，將jar包發布到測試的Maven私服，或者正式環境的Maven私服。


7、回到GitEgg-Cloud項目，在gitegg-service下的pom.xml里面引入gitegg-platform-db和gitegg-platform-mybatis

<!--?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">
    <parent>
        <artifactid>GitEgg-Cloud</artifactid>
        <groupid>com.gitegg.cloud</groupid>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelversion>4.0.0</modelversion>

    <artifactid>gitegg-service</artifactid>
    <packaging>pom</packaging>
    <modules>
        <module>gitegg-service-base</module>
        <module>gitegg-service-bigdata</module>
        <module>gitegg-service-system</module>
    </modules>

    <dependencies>
        <!-- gitegg數據庫驅動及連接池 -->
        <dependency>
            <groupid>com.gitegg.platform</groupid>
            <artifactid>gitegg-platform-db</artifactid>
        </dependency>
        <!-- gitegg mybatis-plus -->
        <dependency>
            <groupid>com.gitegg.platform</groupid>
            <artifactid>gitegg-platform-mybatis</artifactid>
        </dependency>
        <!-- spring boot web核心包 -->
        <dependency>
            <groupid>org.springframework.boot</groupid>
            <artifactid>spring-boot-starter-web</artifactid>
        </dependency>
        <!-- spring boot 健康監控 -->
        <dependency>
            <groupid>org.springframework.boot</groupid>
            <artifactid>spring-boot-starter-actuator</artifactid>
        </dependency>
    </dependencies>

</project>

8、在gitegg-service-system工程下修改application.yml，增加數據庫連接和mybatis的配置：

server:
  port: 8001
spring:
  application:
    name: gitegg-service-system
    datasource:
      type: com.alibaba.druid.pool.DruidDataSource
      driverClassName: com.mysql.jdbc.Driver
      url: jdbc:mysql://127.0.0.1/gitegg_cloud?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&autoReconnect=true
      username: root
      password: root
      initialSize: 1
      minIdle: 3
      maxActive: 20
      # 配置獲取連接等待超時的時間
      maxWait: 60000
      # 配置間隔多久才進行一次檢測，檢測需要關閉的空閑連接，單位是毫秒
      timeBetweenEvictionRunsMillis: 60000
      # 配置一個連接在池中最小生存的時間，單位是毫秒
      minEvictableIdleTimeMillis: 30000
      validationQuery: select 'x'
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      # 打開PSCache，並且指定每個連接上PSCache的大小
      poolPreparedStatements: true
      maxPoolPreparedStatementPerConnectionSize: 20
      # 配置監控統計攔截的filters，去掉后監控界面sql無法統計，'wall'用於防火牆
      filters: config,stat,slf4j
      # 通過connectProperties屬性來打開mergeSql功能；慢SQL記錄
      connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000;
      # 合並多個DruidDataSource的監控數據
      useGlobalDataSourceStat: true
mybatis-plus:
      mapper-locations: classpath*:/com/gitegg/*/*/mapper/*Mapper.xml
      typeAliasesPackage: com.gitegg.*.*.entity
      global-config:
        #主鍵類型  0:"數據庫ID自增", 1:"用戶輸入ID",2:"全局唯一ID (數字類型唯一ID)", 3:"全局唯一ID UUID";
        id-type: 2
        #字段策略 0:"忽略判斷",1:"非 NULL 判斷"),2:"非空判斷"
        field-strategy: 2
        #駝峰下划線轉換
        db-column-underline: true
        #刷新mapper 調試神器
        refresh-mapper: true
        #數據庫大寫下划線轉換
        #capital-mode: true
        #邏輯刪除配置
        logic-delete-value: 1
        logic-not-delete-value: 0
      configuration:
        map-underscore-to-camel-case: true
        cache-enabled: false

9、修改GitEggSystemApplication，添加要掃描的mapper路徑聲明：

package com.gitegg.service.system;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * gitegg-system 啟動類
 */
@MapperScan("com.gitegg.*.*.mapper")
@SpringBootApplication
public class GitEggSystemApplication {

    public static void main(String[] args) {
        SpringApplication.run(GitEggSystemApplication.class,args);
    }

}

10、修改GitEgg-Platform工程中的gitegg-platform-db和gitegg-platform-mybatis，新增mybatis-plus分頁配置，和Druid數據庫連接配置，此配置類預留，后面需要自定義修改。

• DruidConfig.java內容如下:

package com.gitegg.platform.db.config;

import org.springframework.context.annotation.Configuration;

@Configuration
public class DruidConfig {

}

• MybatisPlusConfig.java內容如下:

package com.gitegg.platform.mybatis.config;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@MapperScan("com.gitegg.**.mapper.**")
public class MybatisPlusConfig {

    /**
     * 新的分頁插件,一緩和二緩遵循mybatis的規則,需要設置 MybatisConfiguration#useDeprecatedExecutor = false
     * 避免緩存出現問題(該屬性會在舊插件移除后一同移除)
     */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }

}

11、增加測試類，通過訪問controller->service->dao層，獲取數據庫數據。新建controller、service、impl、mapper、entity、dto包，這些包和類，后面可以用系統自動生成，不需要每次都自己手動建立。

• SystemController.java文件內容：

package com.gitegg.service.system.controller;

import com.gitegg.service.system.service.ISystemService;
import lombok.AllArgsConstructor;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping(value = "system")
@AllArgsConstructor
public class SystemController {

    private final ISystemService systemService;

    @GetMapping(value = "list")
    public Object list() {
        return systemService.list();
    }


    @GetMapping(value = "page")
    public Object page() {
        return systemService.page();
    }
}

• ISystemService.java文件內容：

package com.gitegg.service.system.service;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.gitegg.service.system.entity.SystemTable;

import java.util.List;

public interface ISystemService {

    List<systemtable> list();

    Page<systemtable> page();
}

• SystemServiceImpl.java 內容：

package com.gitegg.service.system.service.impl;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.gitegg.service.system.entity.SystemTable;
import com.gitegg.service.system.mapper.SystemTableMapper;
import com.gitegg.service.system.service.ISystemService;
import lombok.AllArgsConstructor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 *
 */
@Service
@AllArgsConstructor
public class SystemServiceImpl implements ISystemService {

    private final SystemTableMapper systemTableMapper;

    @Override
    public List<systemtable> list() {
        return systemTableMapper.list();
    }

    @Override
    public Page<systemtable> page() {
        Page<systemtable> page = new Page<>(1, 10);
        List<systemtable> records = systemTableMapper.page(page);
        page.setRecords(records);
        return page;
    }
}

• SystemTableMapper.java內容：

package com.gitegg.service.system.mapper;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.gitegg.service.system.entity.SystemTable;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface SystemTableMapper {

    List<systemtable> list();

    List<systemtable> page(Page<systemtable> page);
}

• SystemTable.java內容：

package com.gitegg.service.system.entity;

import lombok.Data;

@Data
public class SystemTable {

    private Long id;

    private String name;

}

• SystemTableMapper.xml內容：

<!--?xml version="1.0" encoding="UTF-8" ?-->

<mapper namespace="com.gitegg.service.system.mapper.SystemTableMapper">

    <select id="list" resulttype="com.gitegg.service.system.entity.SystemTable">
        select * from system_table
    </select>

    <select id="page" resulttype="com.gitegg.service.system.entity.SystemTable">
        select * from system_table
    </select>
</mapper>

12、運行GitEggSystemApplication，在控制台看是否啟動成功，如果啟動成功，在瀏覽器中分別訪問http://127.0.0.1:8001/system/list和http://127.0.0.1:8001/system/page，可以看到數據里面的數據：

本文源碼在https://gitee.com/wmz1930/GitEgg的chapter-05分支。