Spring Boot 集成Sharding-jdbc + Mybatis-Plus实现分库分表

痛定思痛。 2021-08-28 16:18 302阅读 0赞

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*作者: Macky\_He*

*来源：blog.csdn.net/Macky\_He/article/details/95754402*

### 一、 Sharding-jdbc简介 ###

Sharding-jdbc是开源的数据库操作中间件；定位为轻量级Java框架，在Java的JDBC层提供的额外服务。它使用客户端直连数据库，以jar包形式提供服务，无需额外部署和依赖，可理解为增强版的JDBC驱动，完全兼容JDBC和各种ORM框架。

官方文档地址：https://shardingsphere.apache.org/document/current/cn/overview/

本文demo实现了分库分表功能。

作者能力有限，如有错误，欢迎各位在评论中指出。不胜感激！

### 二、项目结构 ###

首先创建一个一般的Spring boot项目，项目采用三层架构，结构图如下：项目目录结构图 POM.xml文件如下：

<?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>
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.6.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.macky</groupId>
        <artifactId>spring-boot-shardingjdbc</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>spring-boot-shardingjdbc</name>
        <description>Demo project for spring-boot-shardingjdbc</description>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <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>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </dependency>
            
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.1.1</version>
            </dependency>
            
            
            <dependency>
                <groupId>io.shardingsphere</groupId>
                <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
                <version>3.1.0</version>
            </dependency>
            
            <dependency>
                <groupId>io.shardingsphere</groupId>
                <artifactId>sharding-jdbc-spring-namespace</artifactId>
                <version>3.1.0</version>
            </dependency>
            
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

实体类以书本为例

package com.macky.springbootshardingjdbc.entity;
    
    import com.baomidou.mybatisplus.annotation.TableName;
    import com.baomidou.mybatisplus.extension.activerecord.Model;
    import groovy.transform.EqualsAndHashCode;
    import lombok.Data;
    import lombok.experimental.Accessors;
    
    /**
     * @author Macky
     * @Title class Book
     * @Description: 书籍是实体类
     * @date 2019/7/13 15:23
     */
    @Data
    @EqualsAndHashCode(callSuper = true)
    @Accessors(chain = true)
    @TableName("book")
    public class Book extends Model<Book> {
        private int id;
        private String name;
        private int count;
    }

开放保存和查询两个接口，代码如下：

package com.macky.springbootshardingjdbc.controller;
    
    import com.macky.springbootshardingjdbc.entity.Book;
    import com.macky.springbootshardingjdbc.service.BookService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.*;
    
    import java.util.List;
    
    /**
     * @author Macky
     * @Title class BookController
     * @Description: TODO
     * @date 2019/7/12 20:53
     */
    @RestController
    public class BookController {
    
        @Autowired
        BookService bookService;
    
        @RequestMapping(value = "/book", method = RequestMethod.GET)
        public List<Book> getItems(){
            return bookService.getBookList();
        }
    
        @RequestMapping(value = "/book",method = RequestMethod.POST)
        public Boolean saveItem(Book book){
            return bookService.save(book);
        }
    }

BookServiceImpl.java
    
    package com.macky.springbootshardingjdbc.service.impl;
    
    import com.baomidou.mybatisplus.core.toolkit.Wrappers;
    import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import com.macky.springbootshardingjdbc.entity.Book;
    import com.macky.springbootshardingjdbc.mapper.BookMapper;
    import com.macky.springbootshardingjdbc.service.BookService;
    import org.springframework.stereotype.Service;
    
    import java.util.List;
    
    /**
     * @author Macky
     * @Title class BookServiceImpl
     * @Description: TODO
     * @date 2019/7/12 20:47
     */
    @Service
    public class BookServiceImpl extends ServiceImpl<BookMapper, Book> implements BookService {
    
        @Override
        public List<Book> getBookList() {
            return baseMapper.selectList(Wrappers.<Book>lambdaQuery());
        }
    
        @Override
        public boolean save(Book book) {
            return super.save(book);
        }
    }

BookMapper.java

package com.macky.springbootshardingjdbc.mapper;
    
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import com.macky.springbootshardingjdbc.entity.Book;
    
    /**
     * @author Macky
     * @Title class BookMapper
     * @Description: TODO
     * @date 2019/7/12 20:46
     */
    public interface BookMapper extends BaseMapper<Book> {
    }

创建数据库表，DDL语句如下

#创建数据库表数据
    CREATE DATABASE IF NOT EXISTS `db0`;
    USE `db0`;
    DROP TABLE IF EXISTS `book_0`;
    CREATE TABLE `book_0` (
        `id` INT ( 11 ) NOT NULL,
        `name` VARCHAR ( 255 ) DEFAULT NULL,
        `count` INT ( 11 ) DEFAULT NULL,
        PRIMARY KEY ( `id` )
    ) ENGINE = INNODB DEFAULT CHARSET = utf8mb4;
    DROP TABLE IF EXISTS `book_1`;
    CREATE TABLE `book_1` (
        `id` INT ( 11 ) NOT NULL,
        `name` VARCHAR ( 255 ) DEFAULT NULL,
        `count` INT ( 11 ) DEFAULT NULL,
        PRIMARY KEY ( `id` )
    ) ENGINE = INNODB DEFAULT CHARSET = utf8mb4;
    
    CREATE DATABASE IF NOT EXISTS `db1`;
    USE `db1`;
    DROP TABLE IF EXISTS `book_0`;
    CREATE TABLE `book_0` (
        `id` INT ( 11 ) NOT NULL,
        `name` VARCHAR ( 255 ) DEFAULT NULL,
        `count` INT ( 11 ) DEFAULT NULL,
        PRIMARY KEY ( `id` )
    ) ENGINE = INNODB DEFAULT CHARSET = utf8mb4;
    DROP TABLE IF EXISTS `book_1`;
    CREATE TABLE `book_1` (
        `id` INT ( 11 ) NOT NULL,
        `name` VARCHAR ( 255 ) DEFAULT NULL,
        `count` INT ( 11 ) DEFAULT NULL,
        PRIMARY KEY ( `id` )
    ) ENGINE = INNODB DEFAULT CHARSET = utf8mb4;
    
    CREATE DATABASE IF NOT EXISTS `db2`;
    USE `db2`;
    DROP TABLE IF EXISTS `book_0`;
    CREATE TABLE `book_0` (
        `id` INT ( 11 ) NOT NULL,
        `name` VARCHAR ( 255 ) DEFAULT NULL,
        `count` INT ( 11 ) DEFAULT NULL,
        PRIMARY KEY ( `id` )
    ) ENGINE = INNODB DEFAULT CHARSET = utf8mb4;
    DROP TABLE IF EXISTS `book_1`;
    CREATE TABLE `book_1` (
        `id` INT ( 11 ) NOT NULL,
        `name` VARCHAR ( 255 ) DEFAULT NULL,
        `count` INT ( 11 ) DEFAULT NULL,
        PRIMARY KEY ( `id` )
    ) ENGINE = INNODB DEFAULT CHARSET = utf8mb4;

配置分库分表策略application.properties：

# 数据源 db0,db1,db2
    sharding.jdbc.datasource.names=db0,db1,db2
    # 第一个数据库
    sharding.jdbc.datasource.db0.type=com.zaxxer.hikari.HikariDataSource
    sharding.jdbc.datasource.db0.driver-class-name=com.mysql.cj.jdbc.Driver
    sharding.jdbc.datasource.db0.jdbc-url=jdbc:mysql://localhost:3306/db0?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    sharding.jdbc.datasource.db0.username=root
    sharding.jdbc.datasource.db0.password=Aa123456
    
    # 第二个数据库
    sharding.jdbc.datasource.db1.type=com.zaxxer.hikari.HikariDataSource
    sharding.jdbc.datasource.db1.driver-class-name=com.mysql.cj.jdbc.Driver
    sharding.jdbc.datasource.db1.jdbc-url=jdbc:mysql://localhost:3306/db1?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    sharding.jdbc.datasource.db1.username=root
    sharding.jdbc.datasource.db1.password=Aa123456
    
    # 第三个数据库
    sharding.jdbc.datasource.db2.type=com.zaxxer.hikari.HikariDataSource
    sharding.jdbc.datasource.db2.driver-class-name=com.mysql.cj.jdbc.Driver
    sharding.jdbc.datasource.db2.jdbc-url=jdbc:mysql://localhost:3306/db2?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    sharding.jdbc.datasource.db2.username=root
    sharding.jdbc.datasource.db2.password=Aa123456
    
    # 水平拆分的数据库（表） 配置分库 + 分表策略 行表达式分片策略
    # 分库策略
    sharding.jdbc.config.sharding.default-database-strategy.inline.sharding-column=id
    sharding.jdbc.config.sharding.default-database-strategy.inline.algorithm-expression=db$->{id % 3}
    
    # 分表策略 其中book为逻辑表 分表主要取决于id行
    sharding.jdbc.config.sharding.tables.book.actual-data-nodes=db$->{0..2}.book_$->{0..2}
    sharding.jdbc.config.sharding.tables.book.table-strategy.inline.sharding-column=count
    # 分片算法表达式
    sharding.jdbc.config.sharding.tables.book.table-strategy.inline.algorithm-expression=book_$->{count % 3}
    
    # 主键 UUID 18位数 如果是分布式还要进行一个设置 防止主键重复
    #sharding.jdbc.config.sharding.tables.user.key-generator-column-name=id
    
    # 打印执行的数据库以及语句
    sharding.jdbc.config.props..sql.show=true
    spring.main.allow-bean-definition-overriding=true
    
    #读写分离
    sharding.jdbc.datasource.dsmaster =

接口测试使用postman

示例：GET请求------>http://localhost:8080/book POST请求：------->http://localhost:8080/book?id=1&name=java编程思想&count=8

demo的github地址：https://github.com/Macky-He/spring-boot--shardingsphere-examples 如各位觉得有帮助的话，还请给个star鼓励鼓励博主，谢谢！

### 三、总结 ###

分库分表实现按照官方文档做一个demo是第一步，如需深入还需要研究源码，研究架构，研究思想；此文仅作为入门demo搭建指南，如需深入理解，还请移步至官方文档。参考资料

1.官方文档：

https://shardingsphere.apache.org/document/current/cn/manual/sharding-jdbc/usage/sharding/

> 这是本人在这几年及春招的总结，历时3个月，我觉得很全面了，对于面试很有帮助，目前，本人已经拿到了腾讯等大厂offer，进入到大厂不是梦想，github 地址:
> 
> **https://github.com/OUYANGSIHAI/JavaInterview**
> 
> 这么辛苦总结，给个**star**好不好。 **点击阅读原文，直达**

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