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sharding jdbc + mybatis +spring boot的分库分表实现

2020-06-03 05:52 645 查看

作者：1994_老叶
链接：https://www.jianshu.com/p/3b2ab87b0de7

一.sharding jdbc简介（这里你可以不看）

首先，我要在这里先介绍一下sharding jdbc：\ Sharding-JDBC定位为轻量级java框架，使用客户端直连数据库，以jar包形式提供服务，未使用中间层，无需额外部署，无其他依赖，DBA也无需改变原有的运维方式，可理解为增强版的JDBC驱动，旧代码迁移成本几乎为零。

它主要的功能：分库分表；读写分离；柔性事务；分布式主键；兼容性；灵活多样的配置；分布式治理能力 (2.0新功能)；

前两个功能无需多说，柔性事务主要表现在：最大努力送达型事务，TCC型事务(TBD)；分布式主键也不需要多说，兼容性主要体现在：可适用于任何基于java的ORM框架，如：JPA, Hibernate, Mybatis, Spring JDBC Template或直接使用JDBC,可基于任何第三方的数据库连接池，如：DBCP, C3P0, BoneCP, Druid等，理论上可支持任意实现JDBC规范的数据库。目前支持MySQL，Oracle，SQLServer和PostgreSQL；灵活多样的配置主要支持这些配置Java，YAML，Inline表达式，Spring命名空间，Spring boot starter；分布式治理能力：配置集中化与动态化，可支持数据源、表与分片策略的动态切换(2.0.0.M1)，客户端的数据库治理，数据源失效自动切换(2.0.0.M2)，基于Open Tracing协议的APM信息输出(2.0.0.M3)，分布式治理能力我也没有尝试过。

从sharding jdbc的官网文档中下载的demo,基本上都不能跑起来，而它的基本文档大部分都粘贴的是代码片段，虽然能理解它的意思，但是很难将这些代码拼接起来，我自己做的时候，也踩了很多坑，在网上搜索的例子很多都是基于当当网的sharding jdbc，基本上版本是到了1.5（在我使用的时候），我当时在使用的时候遇到一些问题，想加官网群，发现加不进去，就去找群主，加群主，并且询问为什么不让加讨论群，后来我才知道那个群主是张亮（当当网架构师，负责sharding jdbc的大牛），还好别人没有理我，太唐突了，后面自己也都把这些问题解决了。不过据说当当网的sharding jdbc抽离出来了，由Apache负责，所以：我的依赖从dangdang的

<dependency>
<groupId>com.dangdang</groupId>
<artifactId>sharding-jdbc-core</artifactId>
<version>1.3.3</version>
</dependency>

变为了：

<dependency>
<groupId>io.shardingjdbc</groupId>
<artifactId>sharding-jdbc-core</artifactId>
<version>2.0.3</version>
</dependency>

我当当网的sharding使用的版本比较低，遇到了一些问题，文章末尾会分享出来。

二.开始动手（这是正文）

废话已经说了那么多了，现在进入正题吧，如何进行sharding jdbc的分库分表，如有错误的地方，欢迎指正。

我使用的工具：编译器：IntelliJ IDEA; mysql管理工具：workbench;

1.我们先建立数据库和表(分别建了两个库两张表)：

CREATE DATABASE `user_0`/*!40100 DEFAULT CHARACTER SET utf8 */;
CREATE TABLE `user_info_1`(
`user_id` bigint(19) NOT NULL,
`user_name` varchar(45) DEFAULT NULL,
`account` varchar(45) NOT NULL,
`password` varchar(45) DEFAULT NULL,
PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `user_info_0`(
`user_id` bigint(19) NOT NULL,
`user_name` varchar(45) DEFAULT NULL,
`account` varchar(45) NOT NULL,
`password` varchar(45) DEFAULT NULL,
PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE DATABASE `user_1`/*!40100 DEFAULT CHARACTER SET utf8 */;
CREATE TABLE `user_info_1`(
`user_id` bigint(19) NOT NULL,
`user_name` varchar(45) DEFAULT NULL,
`account` varchar(45) NOT NULL,
`password` varchar(45) DEFAULT NULL,
PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `user_info_0`(
`user_id` bigint(19) NOT NULL,
`user_name` varchar(45) DEFAULT NULL,
`account` varchar(45) NOT NULL,
`password` varchar(45) DEFAULT NULL,
PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2.开始我们项目的建立，首先明确一点的，我们添加配置的顺序要有先后，思路要清晰，不然在你出错的时候，你都不知道朝哪个方向去思考，我们是spring boot+mybatis+sharding jdbc,我们首先是一个spring boot的项目，所以我们首先建立一个spring boot项目，你可以从https://start.spring.io这个网址去创建一个spring boot项目，也可以从idea编译器上：File->new->project

创建项目.PNG\ 最后生成的pom文件：

<?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.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!--sharding-jdbc -->
<!--<dependency>-->
<!--<groupId>com.dangdang</groupId>-->
<!--<artifactId>sharding-jdbc-core</artifactId>-->
<!--<version>1.3.3</version>-->
<!--</dependency>-->
<dependency>
<groupId>io.shardingjdbc</groupId>
<artifactId>sharding-jdbc-core</artifactId>
<version>2.0.3</version>
</dependency><dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.3</version>
</dependency>
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.44</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>

其中，spring-boot-devtools，commons-dbcp，druid，我感觉都是不需要的，我完成项目后也没对这些项目的依赖进行过滤。

这个时候，你可以测试一下，你的spring boot项目能否正常启动，可以，你就进入到下一步的配置当中。

3.mybatis的配置

首先，看看我的源码的目录结构：

目录结构.PNG

我创建一个entity包（实体包）,里面有一个UserInfo的类：

public class UserInfo {
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column user_info.user_id
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
private Long userId;
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column user_info.user_name
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
private String userName;
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column user_info.account
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
private String account;
/**
*
* This field was generated by MyBatis Generator.
* This field corresponds to the database column user_info.password
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
private String password;
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column user_info.user_id
*
* @return the value of user_info.user_id
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
public Long getUserId() {
return userId;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column user_info.user_id
*
* @param userId the value for user_info.user_id
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
public void setUserId(Long userId) {
this.userId = userId;
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column user_info.user_name
*
* @return the value of user_info.user_name
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
public String getUserName() {
return userName;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column user_info.user_name
*
* @param userName the value for user_info.user_name
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
public void setUserName(String userName) {
this.userName = userName == null ? null : userName.trim();
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column user_info.account
*
* @return the value of user_info.account
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
public String getAccount() {
return account;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column user_info.account
*
* @param account the value for user_info.account
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
public void setAccount(String account) {
this.account = account == null ? null : account.trim();
}
/**
* This method was generated by MyBatis Generator.
* This method returns the value of the database column user_info.password
*
* @return the value of user_info.password
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
public String getPassword() {
return password;
}
/**
* This method was generated by MyBatis Generator.
* This method sets the value of the database column user_info.password
*
* @param password the value for user_info.password
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
public void setPassword(String password) {
this.password = password == null ? null : password.trim();
}
}

然后我有一个mapper包（映射包）,里面有一个映射类UserInfoMapper

import com.example.demo.entity.UserInfo;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface UserInfoMapper {
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user_info
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
int insert(UserInfo record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user_info
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
int insertSelective(UserInfo record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user_info
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
UserInfo selectByPrimaryKey(Long userId);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user_info
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
int updateByPrimaryKeySelective(UserInfo record);
/**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user_info
*
* @mbg.generated Tue Mar 13 23:47:19 CST 2018
*/
int updateByPrimaryKey(UserInfo record);
}

还有再resources目录下的mapper目录中的UserInfoMapper.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.demo.mapper.UserInfoMapper">
<resultMap id="BaseResultMap" type="com.example.demo.entity.UserInfo">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Tue Mar 13 23:47:19 CST 2018.
-->
<id column="user_id" jdbcType="BIGINT" property="userId" />
<result column="user_name" jdbcType="VARCHAR" property="userName" />
<result column="account" jdbcType="VARCHAR" property="account" />
<result column="password" jdbcType="VARCHAR" property="password" />
</resultMap>
<sql id="Base_Column_List">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Tue Mar 13 23:47:19 CST 2018.
-->
user_id, user_name, account, password
</sql>
<select id="selectByPrimaryKey" parameterType="java.lang.Long" resultMap="BaseResultMap">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Tue Mar 13 23:47:19 CST 2018.
-->
select
<include refid="Base_Column_List" />
from user_info
where user_id = #{userId,jdbcType=BIGINT}
</select>
<insert id="insert" parameterType="com.example.demo.entity.UserInfo">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Tue Mar 13 23:47:19 CST 2018.
-->
insert into user_info (user_id, user_name, account,
password)
values (#{userId,jdbcType=BIGINT}, #{userName,jdbcType=VARCHAR}, #{account,jdbcType=VARCHAR},
#{password,jdbcType=VARCHAR})
</insert>
<insert id="insertSelective" parameterType="com.example.demo.entity.UserInfo">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Tue Mar 13 23:47:19 CST 2018.
-->
insert into user_info
<trim prefix="(" suffix=")" suffixOverrides=",">
<if test="userId != null">
user_id,
</if>
<if test="userName != null">
user_name,
</if>
<if test="account != null">
account,
</if>
<if test="password != null">
password,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides=",">
<if test="userId != null">
#{userId,jdbcType=BIGINT},
</if>
<if test="userName != null">
#{userName,jdbcType=VARCHAR},
</if>
<if test="account != null">
#{account,jdbcType=VARCHAR},
</if>
<if test="password != null">
#{password,jdbcType=VARCHAR},
</if>
</trim>
</insert>
<update id="updateByPrimaryKeySelective" parameterType="com.example.demo.entity.UserInfo">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Tue Mar 13 23:47:19 CST 2018.
-->
update user_info
<set>
<if test="userName != null">
user_name = #{userName,jdbcType=VARCHAR},
</if>
<if test="account != null">
account = #{account,jdbcType=VARCHAR},
</if>
<if test="password != null">
password = #{password,jdbcType=VARCHAR},
</if>
</set>
where user_id = #{userId,jdbcType=BIGINT}
</update>
<update id="updateByPrimaryKey" parameterType="com.example.demo.entity.UserInfo">
<!--
WARNING - @mbg.generated
This element is automatically generated by MyBatis Generator, do not modify.
This element was generated on Tue Mar 13 23:47:19 CST 2018.
-->
update user_info
set user_name = #{userName,jdbcType=VARCHAR},
account = #{account,jdbcType=VARCHAR},
password = #{password,jdbcType=VARCHAR}
where user_id = #{userId,jdbcType=BIGINT}
</update>
</mapper>

按道理说，这样的配置应该就可以了，你写个测试代码试一试，能不能进行增删查改，应该是可以的，可我运气比较差，居然不行，所以我又加了一个mybatis-config.xml的配置，我不知道你们运行的结果怎么样，但是现在如果出问题，一定在mybatis上，所以问题搜索的范围就相对只有这一个模块

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--<environments default="development">-->
<!--<environment id="development">-->
<!--<transactionManager type="JDBC"/>-->
<!--<dataSource type="POOLED">-->
<!--<property name="driver" value="${driver-class-name}"/>-->
<!--<property name="url" value="${url}"/>-->
<!--<property name="username" value="${username}"/>-->
<!--<property name="password" value="${password}"/>-->
<!--</dataSource>-->
<!--</environment>-->
<!--</environments>-->
<typeAliases>
<package name="com.example.demo.entity"/>
</typeAliases>
<mappers>
<mapper resource="mapper/UserInfoMapper.xml"/>
</mappers>
</configuration>

4.sharding jdbc的配置\ 当你mybatis调整好了的时候，这个时候就该加sharding jdbc的配置了，接下如果出问题，应该先朝sharding jdbc的方向去考虑.\ 从目录结构中我们可以看到，我有一个config包，我把我的配置都写在这里面的，首先，我们先实现我们的分库分表的策略\ 分库策略的类，DemoDatabaseShardingAlgorithm

package com.example.demo.config;
import com.google.common.collect.Range;
import io.shardingjdbc.core.api.algorithm.sharding.PreciseShardingValue;
import io.shardingjdbc.core.api.algorithm.sharding.standard.PreciseShardingAlgorithm;
import java.util.Collection;
import java.util.LinkedHashSet;
public class DemoDatabaseShardingAlgorithm implements PreciseShardingAlgorithm<Long> {
@Override
public String doSharding(Collection<String> collection, PreciseShardingValue<Long> preciseShardingValue) {
for (String each : collection) {
if (each.endsWith(Long.parseLong(preciseShardingValue.getValue().toString()) % 2+"")) {
return each;
}
}
throw new IllegalArgumentException();
}
//public class DemoDatabaseShardingAlgorithm implements SingleKeyDatabaseShardingAlgorithm<Long> {
//
//    @Override
//    public String doEqualSharding(Collection<String> databaseNames, ShardingValue<Long> shardingValue) {
//
//        for (String each : databaseNames) {
//            if (each.endsWith(Long.parseLong(shardingValue.getValue().toString()) % 2 + "")) {
//                return each;
//            }
//        }
//        throw new IllegalArgumentException();
//    }
//
//    @Override
//    public Collection<String> doInSharding(Collection<String> databaseNames, ShardingValue<Long> shardingValue) {
//        Collection<String> result = new LinkedHashSet<>(databaseNames.size());
//        for (Long value : shardingValue.getValues()) {
//            for (String tableName : databaseNames) {
//                if (tableName.endsWith(value % 2 + "")) {
//                    result.add(tableName);
//                }
//            }
//        }
//        return result;
//    }
//
//    @Override
//    public Collection<String> doBetweenSharding(Collection<String> databaseNames, ShardingValue<Long> shardingValue) {
//        Collection<String> result = new LinkedHashSet<>(databaseNames.size());
//        Range<Long> range = (Range<Long>) shardingValue.getValueRange();
//        for (Long i = range.lowerEndpoint(); i <= range.upperEndpoint(); i++) {
//            for (String each : databaseNames) {
//                if (each.endsWith(i % 2 + "")) {
//                    result.add(each);
//                }
//            }
//        }
//        return result;
//    }
}

使用io.shardingjdbc，就应该实现PreciseShardingAlgorithm接口，然后实现doSharding方法，对应SQL中的=, IN，还有RangeShardingAlgorithm接口中，对应SQL中的BETWEEN AND，因为我只需要=，in操作，所以只实现了PreciseShardingAlgorithm接口，你如果都需要，你可以都实现（千万不要忽略了一个类可以实现多个接口）。\ 如果你使用的当当网的sharding jdbc，那么你需要实现SingleKeyDatabaseShardingAlgorithm这个接口，实现其中的三个方法，我注释到的部分就是原来我用当当网的sharding jdbc的实现。\ 分表策略的类，DemoTableShardingAlgorithm

package com.example.demo.config;
import com.google.common.collect.Range;
import io.shardingjdbc.core.api.algorithm.sharding.PreciseShardingValue;
import io.shardingjdbc.core.api.algorithm.sharding.standard.PreciseShardingAlgorithm;
import java.util.Collection;
import java.util.LinkedHashSet;
//public class DemoTableShardingAlgorithm implements SingleKeyTableShardingAlgorithm<Long> {
public class DemoTableShardingAlgorithm implements PreciseShardingAlgorithm<Long> {
@Override
public String doSharding(Collection<String> collection, PreciseShardingValue<Long> preciseShardingValue) {
for (String each : collection) {
if (each.endsWith(Long.parseLong(preciseShardingValue.getValue().toString()) % 2+"")) {
return each;
}
}
throw new IllegalArgumentException();
}
//    private static Long timeNode1 = 13L;
//
//    /**
//     * select * from t_order where user_id = 11；类似这个意思
//     * @param tableNames
//     * @param shardingValue
//     * @return
//     */
//    @Override
//    public String doEqualSharding(Collection<String> tableNames, ShardingValue<Long> shardingValue) {
//        for (String each : tableNames) {
//            Long currentTime = shardingValue.getValue()>>23;
//            if (currentTime<=timeNode1){
//                if (each.endsWith(shardingValue.getValue() % 2 + "")) {
//                    return each;
//                }
//            }else {
//                if (each.endsWith(shardingValue.getValue() % 2 + "_1")) {
//                    return each;
//                }
//            }
//        }
//        throw new IllegalArgumentException();
//
//    }
//
//    /**
//     * where user_id in (1,23,7)
//     * @param tableNames
//     * @param shardingValue
//     * @return
//     */
//    @Override
//    public Collection<String> doInSharding(Collection<String> tableNames, ShardingValue<Long> shardingValue) {
//        Collection<String> result = new LinkedHashSet<>(tableNames.size());
//        for (Long value : shardingValue.getValues()) {
//            for (String tableName : tableNames) {
//                if (tableName.endsWith(value % 2 + "")) {
//                    result.add(tableName);
//                }
//            }
//        }
//        return result;
//
//    }
//
//    /**
//     * where user_id between(1, 6)
//     *
//     * @param tableNames
//     * @param shardingValue
//     * @return
//     */
//    @Override
//    public Collection<String> doBetweenSharding(Collection<String> tableNames, ShardingValue<Long> shardingValue) {
//        Collection<String> result = new LinkedHashSet<>(tableNames.size());
//        Range<Long> range = (Range<Long>) shardingValue.getValueRange();
//        for (Long i = range.lowerEndpoint(); i <= range.upperEndpoint(); i++) {
//            for (String each : tableNames) {
//                if (each.endsWith(i % 2 + "")) {
//                    result.add(each);
//                }
//            }
//        }
//        return result;
//
//    }
}

与分库的步骤一致，也是需要实现PreciseShardingAlgorithm和RangeShardingAlgorithm两个接口的类。\ 剩下的就是最重要的部分，sharding jdbc的配置：\ DataSourceConfig：

package com.example.demo.config;
import io.shardingjdbc.core.api.config.ShardingRuleConfiguration;
import io.shardingjdbc.core.api.config.TableRuleConfiguration;
import io.shardingjdbc.core.api.config.strategy.StandardShardingStrategyConfiguration;
import io.shardingjdbc.core.jdbc.core.datasource.ShardingDataSource;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;
import java.sql.SQLException;
import java.util.*;
@Configuration
@MapperScan(basePackages = "com.example.demo.mapper", sqlSessionTemplateRef = "testSqlSessionTemplate")
public class DataSourceConfig {
/**
* 配置分库分表策略
*
* @return
* @throws SQLException
*/
@Bean(name = "shardingDataSource")
DataSource getShardingDataSource() throws SQLException {
ShardingRuleConfiguration shardingRuleConfig;
shardingRuleConfig = new ShardingRuleConfiguration();
shardingRuleConfig.getTableRuleConfigs().add(getUserTableRuleConfiguration());
shardingRuleConfig.getBindingTableGroups().add("user_info");
shardingRuleConfig.setDefaultDatabaseShardingStrategyConfig(new StandardShardingStrategyConfiguration("user_id", DemoDatabaseShardingAlgorithm.class.getName()));
shardingRuleConfig.setDefaultTableShardingStrategyConfig(new StandardShardingStrategyConfiguration("user_id", DemoTableShardingAlgorithm.class.getName()));
return new ShardingDataSource(shardingRuleConfig.build(createDataSourceMap()));
}
/**
* 设置表的node
* @return
*/
@Bean
TableRuleConfiguration getUserTableRuleConfiguration() {
TableRuleConfiguration orderTableRuleConfig = new TableRuleConfiguration();
orderTableRuleConfig.setLogicTable("user_info");
orderTableRuleConfig.setActualDataNodes("user_${0..1}.user_info_${0..1}");
orderTableRuleConfig.setKeyGeneratorColumnName("user_id");
return orderTableRuleConfig;
}
/**
* 需要手动配置事务管理器
*
* @param shardingDataSource
* @return
*/
@Bean
public DataSourceTransactionManager transactitonManager(DataSource shardingDataSource) {
return new DataSourceTransactionManager(shardingDataSource);
}
@Bean
@Primary
public SqlSessionFactory sqlSessionFactory(DataSource shardingDataSource) throws Exception {
SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
bean.setDataSource(shardingDataSource);
bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/*.xml"));
return bean.getObject();
}
@Bean
@Primary
public SqlSessionTemplate testSqlSessionTemplate(SqlSessionFactory sqlSessionFactory) throws Exception {
return new SqlSessionTemplate(sqlSessionFactory);
}
private Map<String, DataSource> createDataSourceMap() {
Map<String, DataSource> result = new HashMap<>();
result.put("user_0", createDataSource("user"));
result.put("user_1", createDataSource("user_1"));
return result;
}
private DataSource createDataSource(final String dataSourceName) {
BasicDataSource result = new BasicDataSource();
result.setDriverClassName(com.mysql.jdbc.Driver.class.getName());
result.setUrl(String.format("jdbc:mysql://localhost:3306/%s", dataSourceName));
result.setUsername("root");
result.setPassword("123456");
return result;
}
}

当你遇到一个问题：意思差不多是，需要一个数据源，但是发现好几个，你可以在\ getShardingDataSource（）这个方法上添加注解：@Primary，设置默认数据源\ 还有一个重中之重的部分，在Applicatian这个启动类中：加上注解\ @EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})\ @EnableTransactionManagement(proxyTargetClass = true)\ 主要是为了防止代码的自动配置

package com.example.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.transaction.annotation.EnableTransactionManagement;
@SpringBootApplication
@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})
@EnableTransactionManagement(proxyTargetClass = true)
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}

5.测试

我写了一个测试服务和一个测试类

测试服务：DemoService

package com.example.demo.service;
import com.example.demo.entity.UserInfo;
import com.example.demo.mapper.UserInfoMapper;
import groovy.util.logging.Slf4j;
import io.shardingjdbc.core.api.HintManager;
import io.shardingjdbc.core.hint.HintManagerHolder;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
@Slf4j
@Service
public class DemoService {
@Resource
UserInfoMapper userInfoMapper;
public static Long userId = 150L;
public void demo() {
System.out.println("Insert--------------");
for (int i = 1; i <= 10; i++) {
UserInfo userInfo = new UserInfo();
userInfo.setUserId(userId);
userInfo.setAccount("Account" + i);
userInfo.setPassword("pass" + i);
userInfo.setUserName("name" + i);
userId++;
if(i==3){
HintManagerHolder.clear();
HintManager hintManager = HintManager.getInstance();
hintManager.addDatabaseShardingValue("user_info", "user_id", 3L);
hintManager.addTableShardingValue("user_info", "user_id", 3L);
System.out.println(userId);
}
userInfoMapper.insert(userInfo);
//
//
}
System.out.println("over..........");
}
}

测试类DemoApplicationTests

package com.example.demo;
import com.example.demo.entity.UserInfo;
import com.example.demo.mapper.UserInfoMapper;
import com.example.demo.service.DemoService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import javax.annotation.Resource;
import java.sql.Timestamp;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
@RunWith(SpringRunner.class)
@SpringBootTest
public class DemoApplicationTests {
@Resource
UserInfoMapper userInfoMaper;
@Resource
DemoService demoService;
@Test
public void contextLoads() {
demoService.demo();
}
}

三.遇到的问题

1.首先，我试着用xml的形式来配置，但是一直没有成功，好像是sharding jdbc对xml的支持不是很好，老点的版本是这样，但是新版的应该有很大的改善；

2.在我进行测试的时候,使用的当当网1.3版本的sharding jdbc，一直提示我在sql语句的带上分片键的值，我确实是带上的，我的代码我确定没有问题，网上也没搜到答案，我就根据报错debug sharding jdbc的源码，经过一天的努力，我发现问题了

是因为我使用的sharding jdbc版本不是1.5以上的版本，所以不是sharding jdbc自带的SQL解析引擎，所以处理SQL的时候使用druid的parameter属性进行SQL中的参数存储，而在高版本的druid中，将parameter替换成inputParameter，而我使用的sharding jdbc仍是使用的parmeter取出参数，所以一直找不到分片键值，升级sharding版本或者降低druid版本就可以了

看图你们就懂了：