mac_girl

Spring Boot + myBatis-plus + nacos(在nacos配置数据源)

上一节我们学习了spring boot整合nacos，知道了nacos具有动态的服务注册、配置管理和服务发现的作用，现在我以数据库的配置为例来演示一下nacos是如何进行数据的的配置管理的。

创建数据库

创建两个数据库一个为mybatis-plus, 一个为test2

建表语句

CREATE TABLE test2.`user` (
  `id` bigint(20) NOT NULL COMMENT '主键ID',
  `user_name` varchar(30) DEFAULT NULL COMMENT '姓名',
  `user_age` int(11) DEFAULT NULL COMMENT '年龄',
  `user_email` varchar(50) DEFAULT NULL COMMENT '邮箱',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

加入依赖

        <!--mysql连接器-->
　　　　<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!-- mybatis-plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>

在学习过程中我很好奇mysql-connector-java和mybatis-plus-boot-starter有什么区别？它们各自的作用是什么？

mysql-connector-java

what? 是mysql的一个客户端，相当于命令行客户端和图形化界面一样。

how? 用于连接数据库、发送sql语句、处理结果集

可参考https://blog.csdn.net/keyboard_/article/details/114337739 这位博主讲得很形象。

mybatis-plus-boot-starter

what? 是基于java的持久化框架

how? 自动装配数据源、提供基本的JDBCTemplate简化数据库的操作、事务控制支持

mybatis-plus-boot-start会引入HiKariCp数据库连接池，自动配置dataSource、transationManager、jdbcTemplate

mysql-connector-java和mybatis-plus-boot-starter的区别

mysql-connector-java是真正操作mysql数据库的客户端，mybatis-plus-boot-starter对JDBCTemplate底层还是调用mysql-connector-java的方法操作数据库

可参考：https://www.cnblogs.com/liyanbofly/p/16515856.html 这位博主讲得也很好

pom.xml

此处我是使用nacos进行服务注册、发现以及配置管理，可参考上一篇文章，spring boot整合nacos

<?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.example</groupId>
        <artifactId>nacos-demo</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>nacos-provider</artifactId>

    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.24</version>
            <optional>true</optional>
        </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>
        <!--nacos注册中心-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--Nacos配置中心-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
　　     <!mysql连接器>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!-- mybatis plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

代码生成

生成mapper、service、model对象

分页插件 GeneratorCodeConfig

package com.example.nacosprovider.generator;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Controller;

@Configuration
public class MybatisPlusConfig {

    /**
     * 分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }
}

 

代码生成 MybatisPlusConfig

package com.example.nacosprovider.generator;

import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.*;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;
import com.baomidou.mybatisplus.generator.engine.FreemarkerTemplateEngine;
import org.apache.commons.lang3.StringUtils;

import java.util.Scanner;

public class GeneratorCodeConfig {
    public static String scanner(String tip) {
        Scanner scanner = new Scanner(System.in);
        StringBuilder help = new StringBuilder();
        help.append("请输入" + tip + "：");
        System.out.println(help.toString());
        if (scanner.hasNext()) {
            String ipt = scanner.next();
            if (StringUtils.isNotEmpty(ipt)) {
                return ipt;
            }
        }
        throw new MybatisPlusException("请输入正确的" + tip + "！");
    }

    public static void main(String[] args) {
        // 代码生成器
        AutoGenerator mpg = new AutoGenerator();

        // 全局配置
        GlobalConfig gc = new GlobalConfig();
        String projectPath = System.getProperty("user.dir");
        gc.setOutputDir(projectPath + "/nacos-provider/src/main/java");
        gc.setAuthor("astupidcoder");
        gc.setOpen(false);
        //实体属性 Swagger2 注解
        gc.setSwagger2(false);
        mpg.setGlobalConfig(gc);

        // 数据源配置
        DataSourceConfig dsc = new DataSourceConfig();
        dsc.setUrl("jdbc:mysql://127.0.0.1:3306/test2?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true");
        dsc.setDriverName("com.mysql.cj.jdbc.Driver");
        dsc.setUsername("root");
        dsc.setPassword("123456");
        mpg.setDataSource(dsc);

        // 包配置
        PackageConfig pc = new PackageConfig();
//        pc.setModuleName(scanner("模块名"));
        pc.setParent("com.example.nacosprovider");
        pc.setEntity("model");
        pc.setMapper("mapper");
        pc.setService("service");
        pc.setServiceImpl("service.impl");
        mpg.setPackageInfo(pc);

        // 自定义配置
//        InjectionConfig cfg = new InjectionConfig() {
//            @Override
//            public void initMap() {
//                // to do nothing
//            }
//        };

        // 如果模板引擎是 freemarker
//        String templatePath = "/templates/mapper.xml.ftl";
        // 如果模板引擎是 velocity
        // String templatePath = "/templates/mapper.xml.vm";

        // 自定义输出配置
//        List<FileOutConfig> focList = new ArrayList<>();
        // 自定义配置会被优先输出
//        focList.add(new FileOutConfig(templatePath) {
//            @Override
//            public String outputFile(TableInfo tableInfo) {
//                // 自定义输出文件名 ， 如果你 Entity 设置了前后缀、此处注意 xml 的名称会跟着发生变化！！
//                return projectPath + "/src/main/resources/mapper/" + pc.getModuleName()
//                        + "/" + tableInfo.getEntityName() + "Mapper" + StringPool.DOT_XML;
//            }
//        });
        /*
        cfg.setFileCreate(new IFileCreate() {
            @Override
            public boolean isCreate(ConfigBuilder configBuilder, FileType fileType, String filePath) {
                // 判断自定义文件夹是否需要创建
                checkDir("调用默认方法创建的目录");
                return false;
            }
        });
        */
//        cfg.setFileOutConfigList(focList);
//        mpg.setCfg(cfg);

        // 配置模板
        TemplateConfig templateConfig = new TemplateConfig();

        // 配置自定义输出模板
        //指定自定义模板路径，注意不要带上.ftl/.vm, 会根据使用的模板引擎自动识别
        // templateConfig.setEntity("templates/entity2.java");
        // templateConfig.setService();
        // templateConfig.setController();

        templateConfig.setXml(null);
        mpg.setTemplate(templateConfig);

        // 策略配置
        StrategyConfig strategy = new StrategyConfig();
        strategy.setNaming(NamingStrategy.underline_to_camel);
        strategy.setColumnNaming(NamingStrategy.underline_to_camel);
        strategy.setSuperEntityClass("com.baomidou.mybatisplus.extension.activerecord.Model");
        strategy.setEntityLombokModel(true);
        strategy.setRestControllerStyle(true);

        strategy.setEntityLombokModel(true);
        // 公共父类
//        strategy.setSuperControllerClass("com.baomidou.ant.common.BaseController");
        // 写于父类中的公共字段
//        strategy.setSuperEntityColumns("id");
        strategy.setInclude(scanner("表名，多个英文逗号分割").split(","));
        strategy.setControllerMappingHyphenStyle(true);
        strategy.setTablePrefix(pc.getModuleName() + "_");
        mpg.setStrategy(strategy);
        //mpg.setTemplateEngine(new FreemarkerTemplateEngine());
        mpg.execute();
    }
}

 

nacos中加入数据源的配置

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/mybatis_plus?useSSL=false&useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=123456
<!--数据源类型-->
spring.datasource.type=com.zaxxer.hikari.HikariDataSource
spring.datasource.hikari.maximum-pool-size=40
spring.datasource.hikari.minimum-idle=10
spring.datasource.hikari.idle-timeout=600000
spring.datasource.hikari.max-lifetime=1800000
spring.datasource.hikari.connection-timeout=500
spring.datasource.hikari.login-timeout=500
spring.datasource.hikari.validation-timeout=1000
spring.datasource.hikari.initialization-fail-timeout=1000
<!--控制台输出sql语句-->
mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
mybatis-plus.mapper-locations=classpath*:/mapper/*Mapper.xml

代码演示

NacosProviderApplication

需要加入@MapperScan扫描路径

package com.example.nacosprovider;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@EnableDiscoveryClient
@SpringBootApplication
@MapperScan("com.example.nacosprovider.mapper")
public class NacosProviderApplication {

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

}

UserController

import com.example.nacosprovider.model.User;
import com.example.nacosprovider.service.IUserService;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * <p>
 *  前端控制器
 * </p>
 *
 * @author astupidcoder
 * @since 2022-10-08
 */
@RestController
@RequestMapping("/user")
public class UserController {

    private IUserService iUserService;

    public UserController(IUserService iUserService) {
        this.iUserService = iUserService;
    }

    @PostMapping("/getById")
    public User getById() {
        return iUserService.getById(1); // 调用了mybatis-plus封装的查询方法
    }

    @PostMapping("/findAllUser")
    public List<User> findAllUser(){
        return iUserService.findAllUser();
    }
}

UserServiceImpl

package com.example.nacosprovider.service.impl;

import com.example.nacosprovider.model.User;
import com.example.nacosprovider.mapper.UserMapper;
import com.example.nacosprovider.service.IUserService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author astupidcoder
 * @since 2022-10-08
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService {

    private UserMapper userMapper;

    public UserServiceImpl(UserMapper userMapper) {
        this.userMapper = userMapper;
    }

    @Override
    public List<User> findAllUser() {
        return userMapper.findAllUser();
    }
}

IUserService

package com.example.nacosprovider.service;

import com.example.nacosprovider.model.User;
import com.baomidou.mybatisplus.extension.service.IService;

import java.util.List;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author astupidcoder
 * @since 2022-10-08
 */
public interface IUserService extends IService<User> {
    public List<User> findAllUser();
}

UserMapper

package com.example.nacosprovider.mapper;

import com.example.nacosprovider.model.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * <p>
 *  Mapper 接口
 * </p>
 *
 * @author astupidcoder
 * @since 2022-10-08
 */
@Repository
public interface UserMapper extends BaseMapper<User> {

    public List<User> findAllUser();

}

UserMapper.xml

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

<mapper namespace="com.example.nacosprovider.mapper.UserMapper">

    <!-- 查找用户信息 -->
    <select id="findAllUser" resultType="com.example.nacosprovider.model.User">
        select * from user
    </select>

</mapper>

查询结果

 

 

 更改nacos配置数据库为test2，无需启动项目直接读取的是test2中的数据，由此也验证了nacos可以动态的进行配置管理

 

 

 

 

posted on 2022-10-08 16:51  宇宙美少女  阅读(2661)  评论(0)  编辑  收藏  举报

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