Mybatis-Plus 实现分库分表
老炮说Java 今天一、 Sharding-jdbc简介二、项目结构接口测试使用postman三、总结参考资料一、 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。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：POM.xml文件如下：<?xml version="1.0" encoding="UTF-8"?> 4.0.0 org.springframework.boot spring-boot-starter-parent 2.1.6.RELEASE com.macky spring-boot-shardingjdbc 0.0.1-SNAPSHOT spring-boot-shardingjdbc Demo project for spring-boot-shardingjdbc <java.version>1.8</java.version> org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-test test mysql mysql-connector-java runtime com.baomidou mybatis-plus-boot-starter 3.1.1 io.shardingsphere sharding-jdbc-spring-boot-starter 3.1.0 io.shardingsphere sharding-jdbc-spring-namespace 3.1.0 org.projectlombok lombok org.springframework.boot spring-boot-maven-plugin 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 { 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 /@RestControllerpublic class BookController { @Autowired BookService bookService; @RequestMapping(value = “/book”, method = RequestMethod.GET) public List getItems(){ return bookService.getBookList(); } @RequestMapping(value = “/book”,method = RequestMethod.POST) public Boolean saveItem(Book book){ return bookService.save(book); }}BookServiceImpl.javapackage 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 /@Servicepublic class BookServiceImpl extends ServiceImpl<BookMapper, Book> implements BookService { @Override public List getBookList() { return baseMapper.selectList(Wrappers.lambdaQuery()); } @Override public boolean save(Book book) { return super.save(book); }}BookMapper.javapackage 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 {}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：> 推荐一个艿艿写的 3000+ Star 的 SpringCloud Alibaba 电商开源项目的仓库：https://github.com/YunaiV/onemall# 数据源 db0,db1,db2sharding.jdbc.datasource.names=db0,db1,db2# 第一个数据库sharding.jdbc.datasource.db0.type=com.zaxxer.hikari.HikariDataSourcesharding.jdbc.datasource.db0.driver-class-name=com.mysql.cj.jdbc.Driversharding.jdbc.datasource.db0.jdbc-url=jdbc:mysql://localhost:3306/db0?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTCsharding.jdbc.datasource.db0.username=rootsharding.jdbc.datasource.db0.password=Aa123456# 第二个数据库sharding.jdbc.datasource.db1.type=com.zaxxer.hikari.HikariDataSourcesharding.jdbc.datasource.db1.driver-class-name=com.mysql.cj.jdbc.Driversharding.jdbc.datasource.db1.jdbc-url=jdbc:mysql://localhost:3306/db1?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTCsharding.jdbc.datasource.db1.username=rootsharding.jdbc.datasource.db1.password=Aa123456# 第三个数据库sharding.jdbc.datasource.db2.type=com.zaxxer.hikari.HikariDataSourcesharding.jdbc.datasource.db2.driver-class-name=com.mysql.cj.jdbc.Driversharding.jdbc.datasource.db2.jdbc-url=jdbc:mysql://localhost:3306/db2?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTCsharding.jdbc.datasource.db2.username=rootsharding.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=idsharding.jdbc.config.sharding.default-database-strategy.inline.algorithm-expression=dbKaTeX parse error: Expected '}', got 'EOF' at end of input: …l-data-nodes=db->{0…2}.book_KaTeX parse error: Expected 'EOF', got '#' at position 94: …ng-column=count#̲ 分片算法表达式shardin…->{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=truespring.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/bookPOST请求：------->http://localhost:8080/book?id=1&name=java编程思想&count=8demo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。参考资料官方文档：https://shardingsphere.apache.org/document/current/cn/manual/sharding-jdbc/usage/sharding/