Spring Boot集成Sharding-jdbc + Mybatis-Plus實現分庫分表

一、 Sharding-jdbc簡介

Sharding-jdbc是開源的數據庫操作中間件；定位為輕量級Java框架，在Java的JDBC層提供的額外服務。它使用客戶端直連數據庫，以jar包形式提供服務，無需額外部署和依賴，可理解為增強版的JDBC驅動，完全兼容JDBC和各種ORM框架。

官方文檔地址：https://shardingsphere.apache.org/document/current/cn/overview/

本文demo實現了分庫分表功能。

作者能力有限，如有錯誤，歡迎各位在評論中指出。不勝感激！

二、項目結構

首先創建一個一般的Spring boot項目，項目採用三層架構，結構圖如下：項目目錄結構圖 POM.xml文件如下：

<code>
<project>         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>/<code>

實體類以書本為例

<code>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: 書籍是實體類
 * @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;
}/<book>/<code>

開放保存和查詢兩個接口，代碼如下：

<code>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);
    }
}/<book>/<code>

<code>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> implements BookService {

    @Override
    public List<book> getBookList() {
        return baseMapper.selectList(Wrappers.<book>lambdaQuery());
    }

    @Override
    public boolean save(Book book) {
        return super.save(book);
    }
}/<book>/<book>/<bookmapper>/<code>

BookMapper.java

<code>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> {
}/<book>/<code>

創建數據庫表，DDL語句如下

<code>#創建數據庫表數據
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;/<code>

配置分庫分表策略application.properties：

<code># 數據源 db0,db1,db2
sharding.jdbc.datasource.names=db0,db1,db2
# 第一個數據庫
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

# 第二個數據庫
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

# 第三個數據庫
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

# 水平拆分的數據庫（表） 配置分庫 + 分表策略 行表達式分片策略
# 分庫策略
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為邏輯表 分表主要取決於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
# 分片算法表達式
sharding.jdbc.config.sharding.tables.book.table-strategy.inline.algorithm-expression=book_$->{count % 3}

# 主鍵 UUID 18位數 如果是分佈式還要進行一個設置 防止主鍵重複
#sharding.jdbc.config.sharding.tables.user.key-generator-column-name=id

# 打印執行的數據庫以及語句
sharding.jdbc.config.props..sql.show=true
spring.main.allow-bean-definition-overriding=true

#讀寫分離
sharding.jdbc.datasource.dsmaster =/<code>

接口測試使用postman

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

demo的github地址：https://github.com/Macky-He/spring-boot--shardingsphere-examples 如各位覺得有幫助的話，還請給個star鼓勵鼓勵博主，謝謝！

三、總結

分庫分表實現按照官方文檔做一個demo是第一步，如需深入還需要研究源碼，研究架構，研究思想；此文僅作為入門demo搭建指南，

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關鍵字: MySQL XML 分庫