使用Mybatis中分表插件shardbatis

1.POM依賴

<dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.30</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.3</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.3.11.RELEASE</version>
    </dependency>

    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.2.1</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.2.3</version>
    </dependency>

        <!-- 分表插件 -->
        <dependency>
            <groupId>org.shardbatis</groupId>
            <artifactId>shardbatis</artifactId>
            <version>2.0.0B</version>
        </dependency>

        <!-- sql解析插件 -->
        <dependency>
            <groupId>net.sf.jsqlparser</groupId>
            <artifactId>jsqlparser</artifactId>
            <version>0.8.0</version>
        </dependency>

        <!-- mybatis pager -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>4.1.0</version>
        </dependency>

這裏需要注意，如果使用 pagehelper 分頁插件和 shardbatis 插件，一定要把pagehelper放在下面！！！！（踩坑）

2.配置文件/配置類

2.1配置類

package com.ils.intelab.video.config;

import com.google.code.shardbatis.builder.ShardConfigHolder;
import com.google.code.shardbatis.builder.ShardConfigParser;
import com.google.code.shardbatis.converter.SqlConverterFactory;
import com.google.code.shardbatis.util.ReflectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.ibatis.executor.statement.RoutingStatementHandler;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.logging.Log;
import org.apache.ibatis.logging.LogFactory;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.plugin.*;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.util.Properties;
import java.util.concurrent.ConcurrentHashMap;

@Intercepts({@Signature(
        type = StatementHandler.class,
        method = "prepare",
        args = {Connection.class,Integer.class}
)})
public class ShardPluginExtend implements Interceptor {

    private static final Log log = LogFactory.getLog(ShardPluginExtend.class);
    public static final String SHARDING_CONFIG = "shardingConfig";
    private static final ConcurrentHashMap<String, Boolean> cache = new ConcurrentHashMap();

    public ShardPluginExtend(){

    }

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        StatementHandler statementHandler = (StatementHandler)invocation.getTarget();
        MappedStatement mappedStatement = null;
        if (statementHandler instanceof RoutingStatementHandler) {
            StatementHandler delegate = (StatementHandler) ReflectionUtils.getFieldValue(statementHandler, "delegate");
            mappedStatement = (MappedStatement)ReflectionUtils.getFieldValue(delegate, "mappedStatement");
        } else {
            mappedStatement = (MappedStatement)ReflectionUtils.getFieldValue(statementHandler, "mappedStatement");
        }

        String mapperId = mappedStatement.getId();
        if (this.isShouldParse(mapperId)) {
            String sql = statementHandler.getBoundSql().getSql();
            if (log.isDebugEnabled()) {
                log.debug("Original Sql [" + mapperId + "]:" + sql);
            }

            Object params = statementHandler.getBoundSql().getParameterObject();
            SqlConverterFactory cf = SqlConverterFactory.getInstance();
            sql = cf.convert(sql, params, mapperId);
            if (log.isDebugEnabled()) {
                log.debug("Converted Sql [" + mapperId + "]:" + sql);
            }

            ReflectionUtils.setFieldValue(statementHandler.getBoundSql(), "sql", sql);
        }

        return invocation.proceed();
    }

    @Override
    public Object plugin(Object target) {
        return Plugin.wrap(target, this);
    }

    @Override
    public void setProperties(Properties properties) {
        String config = properties.getProperty("shardingConfig", (String)null);
        if (config != null && config.trim().length() != 0) {
            ShardConfigParser parser = new ShardConfigParser();
            InputStream input = null;

            try {
                input = Resources.getResourceAsStream(config);
                parser.parse(input);
            } catch (IOException var14) {
                log.error("Get sharding config file failed.", var14);
                throw new IllegalArgumentException(var14);
            } catch (Exception var15) {
                log.error("Parse sharding config file failed.", var15);
                throw new IllegalArgumentException(var15);
            } finally {
                if (input != null) {
                    try {
                        input.close();
                    } catch (IOException var13) {
                        log.error(var13.getMessage(), var13);
                    }
                }

            }

        } else {
            throw new IllegalArgumentException("property 'shardingConfig' is requested.");
        }
    }

    private boolean isShouldParse(String mapperId) {
        if(StringUtils.isNotBlank(mapperId)){
            mapperId = mapperId.substring(mapperId.lastIndexOf('.', (mapperId.lastIndexOf(".") - 1)) + 1);
        }
        Boolean parse = (Boolean)cache.get(mapperId);
        if (parse != null) {
            return parse;
        } else {
            if (!mapperId.endsWith("!selectKey")) {
                ShardConfigHolder configHolder = ShardConfigHolder.getInstance();
                if (!configHolder.isIgnoreId(mapperId) && (!configHolder.isConfigParseId() || configHolder.isParseId(mapperId))) {
                    parse = true;
                }
            }

            if (parse == null) {
                parse = false;
            }

            cache.put(mapperId, parse);
            return parse;
        }
    }
}

package com.ils.intelab.video.config;

import com.baomidou.mybatisplus.core.injector.ISqlInjector;
import com.baomidou.mybatisplus.core.parser.ISqlParser;
import com.baomidou.mybatisplus.extension.injector.LogicSqlInjector;
import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.ArrayList;
import java.util.List;
import java.util.Properties;


@Configuration
@MapperScan({"com.ils.intelab.video.dao"})
public class MybatisPlusConfig {

    @Bean(name = "shardPlugin")
    public ShardPluginExtend shardPlugin() {
        ShardPluginExtend shardPlugin = new ShardPluginExtend();
        Properties properties = new Properties();
        //文件加載--鍵值必須爲shardingConfig，這是類的內部要求，否則加載失敗
        properties.put("shardingConfig", "shard/shard_config.xml");
        shardPlugin.setProperties(properties);
        return shardPlugin;
    }

	/**
	 * 分頁插件
	 *
	 * @return PaginationInterceptor
	 */
	@Bean
	@ConditionalOnMissingBean
	public PaginationInterceptor paginationInterceptor() {
		PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
		List<ISqlParser> sqlParserList = new ArrayList<>();
		paginationInterceptor.setSqlParserList(sqlParserList);
		return paginationInterceptor;
	}

	/**
	 * 邏輯刪除插件
	 *
	 * @return LogicSqlInjector
	 */
	@Bean
	@ConditionalOnMissingBean
	public ISqlInjector sqlInjector() {
		return new LogicSqlInjector();
	}
}

2.2配置文件（測試）

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE shardingConfig PUBLIC "-//shardbatis.googlecode.com//DTD Shardbatis 2.0//EN"
		"http://shardbatis.googlecode.com/dtd/shardbatis-config.dtd">
<shardingConfig>
	<!-- 忽略不進行分表策略的mapperid-即對應的方法 -->
	<ignoreList>
		<value></value>
	</ignoreList>

	<!-- 進行分表策略的mapperid-即對應的方法;一定要精確到方法，否則不會被攔截 -->
	<parseList>
		<value>VideoDataMotionMapper.getALLMotionVideoDate</value>
	</parseList>

	<!-- 指定表使用對應的策略 -->
	<strategy tableName="video_data_motion"	strategyClass="com.ils.intelab.video.shard.VideoDataShardStrategyImpl" />

</shardingConfig>

3.ShardStrategy接口實現（測試）

package com.ils.intelab.video.shard;

import com.alibaba.fastjson.JSONObject;
import com.google.code.shardbatis.strategy.ShardStrategy;
import com.ils.intelab.common.utils.JsonMapperUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

/**
 * @Classname VideoDataShardStrategyImpl
 * @Description TODO
 * @Date 2020/5/6 14:48
 * @Created zzf
 */
@Component
@Slf4j
public class VideoDataShardStrategyImpl implements ShardStrategy {
    @Override
    public String getTargetTableName(String baseTableName, Object params, String mapperId) {
        String jsonResult = JsonMapperUtil.obj2String(params);
        JSONObject jsonObject = JSONObject.parseObject(jsonResult);
        int deviceSerial = jsonObject.get("deviceSerial").toString().hashCode();
            Integer tableNum = deviceSerial % 4;
            Integer databaseNum = deviceSerial % 2;
            baseTableName = baseTableName.split("_")[0] + "_" + databaseNum + "." + baseTableName + "_" + tableNum;
        return baseTableName;
    }
}

這裏我根據它的hashcode去做！

測試如下：