spring 配置双数据源并读写分离

                      摘自 开源项目Ibase4j

   关键思想在于AbstractRoutingSource 类 还有方法名称和切入点去控制使用哪个数据源

   1.首先在配置文件配置多个数据源 并且交给继承自spring AbstractRoutingSource去管理 

   datasource.xml配置如下

     

<?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:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-4.0.xsd  
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-4.0.xsd">
    <bean id="stat-filter" class="com.alibaba.druid.filter.stat.StatFilter" lazy-init="true">
        <description>状态过滤器</description>
        <property name="slowSqlMillis" value="3000" />
        <property name="logSlowSql" value="true" />
        <property name="mergeSql" value="true" />
    </bean>
    <bean id="readDataSource" class="com.alibaba.druid.pool.DruidDataSource"
        destroy-method="close" init-method="init" lazy-init="true">
        <description>只读数据库连接</description>
        <property name="driverClassName" value="${db.driver}" />
        <property name="url" value="${db.reader.url}" />
        <property name="username" value="${db.reader.username}" />
        <property name="password" value="${db.reader.password}" />
        <!-- 初始化连接大小 -->
        <property name="initialSize" value="${db.initialSize}" />
        <!-- 连接池最大数量 -->
        <property name="maxActive" value="${db.maxActive}" />
        <!-- 连接池最小空闲 -->
        <property name="minIdle" value="${db.minIdle}" />
        <!-- 获取连接最大等待时间 -->
        <property name="maxWait" value="${db.maxWait}" />
        <!-- -->
        <property name="defaultReadOnly" value="true" />
        <property name="proxyFilters">
            <list>
                <ref bean="stat-filter" />
            </list>
        </property>
        <property name="filters" value="${druid.filters}" />
        <property name="testWhileIdle" value="true" />
        <property name="testOnBorrow" value="false" />
        <property name="testOnReturn" value="false" />
        <property name="validationQuery" value="SELECT 'x'" />
        <property name="timeBetweenLogStatsMillis" value="60000" />
        <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
        <property name="minEvictableIdleTimeMillis" value="${db.minEvictableIdleTimeMillis}" />
        <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
        <property name="timeBetweenEvictionRunsMillis" value="${db.timeBetweenEvictionRunsMillis}" />
    </bean>
    <bean id="writeDataSource" class="com.alibaba.druid.pool.DruidDataSource"
        destroy-method="close" init-method="init" lazy-init="true">
        <description>只写数据库连接</description>
        <property name="driverClassName" value="${db.driver}" />
        <property name="url" value="${db.writer.url}" />
        <property name="username" value="${db.writer.username}" />
        <property name="password" value="${db.writer.password}" />
        <property name="initialSize" value="${db.initialSize}" />
        <property name="maxActive" value="${db.maxActive}" />
        <property name="minIdle" value="${db.minIdle}" />
        <property name="maxWait" value="${db.maxWait}" />
        <property name="defaultReadOnly" value="false" />
        <property name="proxyFilters">
            <list>
                <ref bean="stat-filter" />
            </list>
        </property>
        <property name="filters" value="${druid.filters}" />
        <property name="testWhileIdle" value="true" />
        <property name="testOnBorrow" value="false" />
        <property name="testOnReturn" value="false" />
        <property name="validationQuery" value="SELECT 'x'" />
        <property name="timeBetweenLogStatsMillis" value="60000" />
        <property name="minEvictableIdleTimeMillis" value="${db.minEvictableIdleTimeMillis}" />
        <property name="timeBetweenEvictionRunsMillis" value="${db.timeBetweenEvictionRunsMillis}" />
    </bean>
   <!--注意这里的配置-->
    <bean id="dataSource" class="org.ibase4j.core.aspect.ChooseDataSource" lazy-init="true">
        <description>数据源</description>
        <property name="targetDataSources">
            <map key-type="java.lang.String" value-type="javax.sql.DataSource">
                <!-- write -->
                <entry key="write" value-ref="writeDataSource" />
                <!-- read -->
                <entry key="read" value-ref="readDataSource" />
            </map>
        </property>
        <property name="defaultTargetDataSource" ref="writeDataSource" />
        <property name="methodType">
            <map key-type="java.lang.String">
                <!-- read -->
                <entry key="read" value=",get,select,count,list,query," />
                <!-- write -->
                <entry key="write" value=",add,insert,create,update,delete,remove," />
            </map>
        </property>
    </bean>

    <!-- 注意这个切面 -->
    <bean class="org.ibase4j.core.aspect.DataSourceAspect" />
    <!--  -->
    <bean class="org.springframework.jdbc.core.JdbcTemplate">
        <constructor-arg ref="dataSource" />
    </bean>
</beans>

接下来事继承类

package org.ibase4j.core.aspect;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang3.StringUtils;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**
 * 获取数据源
 * 
 * @author ShenHuaJie
 * @version 2016年5月20日 下午3:17:16
 */
public class ChooseDataSource extends AbstractRoutingDataSource {
    public static Map<String, List<String>> METHODTYPE = new HashMap<String, List<String>>();

    // 获取数据源名称
    protected Object determineCurrentLookupKey() {
        return HandleDataSource.getDataSource();
    }

    // 设置方法名前缀对应的数据源
    public void setMethodType(Map<String, String> map) {
        for (String key : map.keySet()) {
            List<String> v = new ArrayList<String>();
            String[] types = map.get(key).split(",");
            for (String type : types) {
                if (StringUtils.isNotBlank(type)) {
                    v.add(type);
                }
            }
            METHODTYPE.put(key, v);
        }
    }
}

接下来切面实现类

package org.ibase4j.core.aspect;

import org.apache.commons.lang3.StringUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

/**
 * 切换数据源(不同方法调用不同数据源)
 * 
 * @author ShenHuaJie
 * @version 2016年5月20日 下午3:17:52
 */
@Aspect
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class DataSourceAspect {
    private final Logger logger = LogManager.getLogger();
    //配置切入点
    @Pointcut("execution(* org.ibase4j.service..*.*(..))")
    public void aspect() {
    }

    /**
     * 配置前置通知,使用在方法aspect()上注册的切入点
     */
    @Before("aspect()")
    public void before(JoinPoint point) {
        String className = point.getTarget().getClass().getName();
        String method = point.getSignature().getName();
        logger.info(className + "." + method + "(" + StringUtils.join(point.getArgs(), ",") + ")");
        try {
            L: for (String key : ChooseDataSource.METHODTYPE.keySet()) {
                for (String type : ChooseDataSource.METHODTYPE.get(key)) {
                    if (method.startsWith(type)) {
                        logger.info(key);
                        HandleDataSource.putDataSource(key);
                        break L;
                    }
                }
            }
        } catch (Exception e) {
            logger.error(e);
            HandleDataSource.putDataSource("write");
        }
    }

    @After("aspect()")
    public void after(JoinPoint point) {
        HandleDataSource.clear();
    }
}

 还有一个帮助你拿到数据元的类

  

package org.ibase4j.core.aspect;

/**
 * @author ShenHuaJie
 * @version 2016年5月20日 下午3:18:04
 */
public class HandleDataSource {
    // 数据源名称线程池
    private static final ThreadLocal<String> holder = new ThreadLocal<String>();

    public static void putDataSource(String datasource) {
        holder.set(datasource);
    }

    public static String getDataSource() {
        return holder.get();
    }

    public static void clear() {
        holder.remove();
    }
}