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summercool-ddl框架简介 (二) 博客分类: Ibatis3springWebHibernate管理  

程序员文章站 2024-02-23 13:24:04
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简介:轻量封装Ibatis3

         因为本人在国内最大的电子商务公司工作期间,深感一个好的分表分库框架可以大大提高系统的承载能力及系统的灵活性,而一个不好的分表分库方案,则让系统在大数据量处理的时候非常郁闷。所以, 在根据笔者在从事电子商务开发的这几年中,对各个应用场景而开发的一个轻量封装Ibatis3的一个分表分库框架。

         笔者工作的这几年之中,总结并开发了如下几个框架: summercool(Web 框架,已经应用于某国内大型网络公司的等重要应用)、summercool-hsf(基于Netty实现的RPC框架,已经应用国内某移动互联网公司)、 summercool-ddl(基于Mybaits的分表分库框架,已经应用国内某移动互联网公司);相继缓存方案、和消息系统解决方案也会慢慢开源。 Summercool框架做为笔者的第一个开源框架

 

1.依赖

<dependency>
    <groupId>org.summercool</groupId>
    <artifactId>summercool-ddl</artifactId>
    <version>1.0</version>
</dependency>

 源码svn地址:http://summercool-ddl.googlecode.com/svn/trunk

2.准备Sql映射文件

<?xml version="1.0" encoding="UTF-8" ?> 
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" ">
<mapper namespace="NS-User">
    <insert id="insertUser" parameterType="org.summercool.mybatis.demo.dao.entity.UserEntity">
        insert into $[user]$(
            id,
            name
        ) values (
            #{id},
            #{name}
        )
    </insert>
</mapper>

 注意此处,对于需要分表或分库的表,使用“$[table name]$”这种方式表示。

3.Spring配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd"
    default-autowire="byName">
    <bean id="dataSourceMaster" class="com.jolbox.bonecp.BoneCPDataSource"
        destroy-method="close">
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUrl">
            <value>${demo.datasource.master.jdbcUrl}</value>
        </property>
        <property name="username" value="${demo.datasource.master.username}" />
        <property name="password" value="${demo.datasource.master.password}" />
        <property name="idleConnectionTestPeriodInMinutes" value="5" />
        <property name="idleMaxAgeInMinutes" value="30" />
        <property name="maxConnectionsPerPartition" value="30" />
        <property name="minConnectionsPerPartition" value="5" />
        <property name="partitionCount" value="2" />
        <property name="acquireIncrement" value="5" />
        <property name="statementsCacheSize" value="150" />
        <property name="releaseHelperThreads" value="8" />
        <property name="connectionTestStatement" value="select 1 from dual" />
    </bean>
     
    <bean id="dataSourceSlave" class="com.jolbox.bonecp.BoneCPDataSource"
        destroy-method="close">
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUrl">
            <value>${demo.datasource.slave.jdbcUrl}</value>
        </property>
        <property name="username" value="${demo.datasource.slave.username}" />
        <property name="password" value="${demo.datasource.slave.password}" />
        <property name="idleConnectionTestPeriodInMinutes" value="5" />
        <property name="idleMaxAgeInMinutes" value="30" />
        <property name="maxConnectionsPerPartition" value="30" />
        <property name="minConnectionsPerPartition" value="5" />
        <property name="partitionCount" value="2" />
        <property name="acquireIncrement" value="5" />
        <property name="statementsCacheSize" value="150" />
        <property name="releaseHelperThreads" value="8" />
        <property name="connectionTestStatement" value="select 1 from dual" />
    </bean>
    <bean id="demoSqlSessionFactory"
        class="org.summercool.mybatis.spring.support.SqlSessionFactoryBean">
        <property name="mainDataSource" ref="dataSourceMaster" />
        <property name="shardDataSourceList">
            <util:list>
                <ref bean="dataSourceSlave" />
            </util:list>
        </property>
        <property name="mapperLocations">
            <array>
                <value>classpath:mybatis/user-mapper.xml</value>
            </array>
        </property>
        <property name="shardStrategy">
            <map>
                <entry key="Shard-User">
                    <value>org.summercool.mybatis.demo.shard.UserShardStrategy</value>
                </entry>
            </map>
        </property>
    </bean>
    <bean id="userDao" class="org.summercool.mybatis.demo.dao.impl.UserDaoImpl">
        <property name="sqlSessionFactory" ref="demoSqlSessionFactory"/>
    </bean>
</beans>
从上面的配置文件中,可以看到,注入了两个DataSource,分别代表两个物理库。

然后再添加类型为org.summercool.mybatis.spring.support.SqlSessionFactoryBean的bean描述,并将两个DataSource关联到该bean的主库和备库(备库可以有多个)字段。

同时,需要设置分表策略字段shardStrategy,该字段的类型是Map,添加分表策略时,Key即为分表策略的名称,Value则为具体的分表策略实现。如上,注册了一个名称为"fr"的分表策略实现类com.gexin.contact.utils.shard.ContactShardStrategy。

4.分表策略的实现

package org.summercool.mybatis.demo.shard;
import java.util.Map;
import javax.sql.DataSource;
import org.summercool.mybatis.ShardParam;
import org.summercool.mybatis.strategy.ShardStrategy;
/**
 * 
 * @author Kolor
 */
public class UserShardStrategy extends ShardStrategy {
    @Override
    public DataSource getTargetDataSource() {
        ShardParam shardParam = getShardParam();
        //
        Long param = (Long) shardParam.getShardValue();
        Map<String, DataSource> map = this.getShardDataSources();
        if (param > 100) {
            return map.get("dataSourceSlave");
        }
        return getMainDataSource();
    }
    @Override
    public String getTargetSql() {
        String targetSql = getSql();
        ShardParam shardParam = getShardParam();
        //
        Long param = (Long) shardParam.getShardValue();
        String tableName = "user_" + (param % 2);
        targetSql = targetSql.replaceAll("\\$\\[user\\]\\$", tableName);
        return targetSql;
    }
}
可以看到这个分表策略继承自org.summercool.mybatis.strategy.ShardStrategy,并实现其两个抽象方法getTargetDataSource和getTargetSql,分别代表获取目标DataSource和获取目标Sql。

目标DataSource通过解析分表参数,按设计好的策略获取。

目标Sql同样通过解析分表参数,生成真正的表名,然后用字符串替换的方式获取真正的Sql。

5.Dao层实现

package org.summercool.mybatis.demo.dao.impl;
import org.summercool.mybatis.ShardParam;
import org.summercool.mybatis.demo.dao.UserDao;
import org.summercool.mybatis.demo.dao.entity.UserEntity;
import org.summercool.mybatis.spring.support.SqlSessionDaoSupport;
/**
 *  
 * @author
 */
public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {
    public boolean insertUser(UserEntity user) {
        ShardParam shardParam = new ShardParam("Shard-User", user.getId(), user);
         
        return getSqlSession().insert("NS-User.insertUser", shardParam) > 0;
    }
}

Dao层实现没有特别的地方,仅有的一点就是,对于需要分表分库的操作,需要传入分表参数(ShardParam)

ShardParam shardParam = new ShardParam("Shard-User", user.getId(), user);

我们来看看ShardParam的定义:

package org.summercool.mybatis;
public class ShardParam {
    public static final ShardParam NO_SHARD = new ShardParam();
    private String name;
    private Object shardValue;
    private Object params;
    public ShardParam() {
    }
    public ShardParam(String name, Object shardValue, Object params) {
        super();
        this.name = name;
        this.shardValue = shardValue;
        this.params = params;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Object getShardValue() {
        return shardValue;
    }
    public void setShardValue(Object shardValue) {
        this.shardValue = shardValue;
    }
    public Object getParams() {
        return params;
    }
    public void setParams(Object params) {
        this.params = params;
    }
}

 构造函数,第一个参数是分表分库策略的名字(即在第二小节中提到的"fr"),第二个参数是分表参数,第三个参数是真正提交到数据库的参数。

6. Spring事务配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:util="http://www.springframework.org/schema/util"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-3.0.xsd 
        http://www.springframework.org/schema/util 
        http://www.springframework.org/schema/util/spring-util-3.0.xsd"
    default-autowire="byName">
     
    <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>classpath:config/config.properties</value>
            </list>
        </property>
        <property name="fileEncoding" value="UTF-8" />
    </bean>
     
    <bean id="userService" class="org.summercool.mybatis.demo.service.impl.UserServiceImpl"/>
     
    <!-- 事务配置 -->
    <bean name="userTransactionManager"
        class="org.summercool.mybatis.spring.support.MultiDataSourceTransactionManager">
    </bean>
    <tx:advice id="userTxAdvice" transaction-manager="userTransactionManager">
        <tx:attributes>
            <tx:method name="*" propagation="NOT_SUPPORTED" />
        </tx:attributes>
    </tx:advice>
     
    <aop:config>
        <!-- UserService事务管理 -->
        <aop:pointcut id="userServiceOperation"
            expression="execution(* org.summercool.mybatis.demo.service..*Service.*(..))" />
        <aop:advisor advice-ref="userTxAdvice" pointcut-ref="userServiceOperation" />
    </aop:config>
</beans>
 目前只支持XA分布式事务。