【JAVA秒会技术之随意切换数据库】Spring如何高效的配置多套数据源

来源：Student_Li 发布时间：2018-11-14 11:19:52 阅读量：822

Spring如何高效的配置多套数据源

真正的开发中，难免要使用多个数据库，进行不同的切换。无论是为了实现“读写分离”也好，还是为了使用不同的数据库（“MySQL”或“Oracle”或“SQLServer”）。传统的方法，是配置多套Spring配置文件与Mysql配置文件,不仅配置起来较为混乱，而且切换及对事物的管理，也很麻烦。下面，博主就介绍一种方法，帮助大家解决“Spring如何高效的配置多套数据源”！

（一）Spring核心配置文件

1.Spring-conf配置文件

<?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" 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.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context.xsd

http://www.springframework.org/schema/tx

http://www.springframework.org/schema/tx/spring-tx.xsd

http://www.springframework.org/schema/aop

http://www.springframework.org/schema/aop/spring-aop.xsd">

<context:annotation-config />

<context:component-scan base-package="com.***.****">

<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />

</context:component-scan>

<list>

<value>classpath:*.properties</value>

</list>

</property>

</bean>

</bean>

</bean>

</bean>

<map>

</map>

</property>

</bean>

<list>

<value>classpath:/mybatis/mapper/*.xml</value>

</list>

</property>

</bean>

</bean>

<aop:aspectj-autoproxy />

</beans>

2.配置jdbc.properties

#------------------------JDBC-------------------------------

jdbc.url:jdbc:sqlserver://ip地址1:端口;database=数据库;integratedSecurity=false

jdbc.driverClassName:com.microsoft.sqlserver.jdbc.SQLServerDriver

jdbc.username:用户名

jdbc.password:密码

jdbc.filters:stat

jdbc.maxActive:10

jdbc.initialSize:2

jdbc.maxWait:60000

jdbc.minIdle:2

jdbc.timeBetweenEvictionRunsMillis:60000

jdbc.minEvictableIdleTimeMillis:300000

jdbc.validationQuery:SELECT 'x' FROM DUAL

jdbc.testWhileIdle:true

jdbc.testOnBorrow:false

jdbc.testOnReturn:false

jdbc.maxOpenPreparedStatements:20

jdbc.removeAbandoned:true

jdbc.removeAbandonedTimeout:180

jdbc.logAbandoned:true

#---------------------------JDBC-2----------------------------

jdbc2.url:jdbc:mysql://ip地址1:端口/数据库?autoReconnect=true

jdbc2.driverClassName:com.mysql.jdbc.Driver

jdbc2.username:用户名

jdbc2.password:密码

jdbc2.filters:stat

jdbc2.maxActive:10

jdbc2.initialSize:2

jdbc2.maxWait:60000

jdbc2.minIdle:2

jdbc2.timeBetweenEvictionRunsMillis:60000

jdbc2.minEvictableIdleTimeMillis:300000

jdbc2.validationQuery:SELECT 'x' FROM DUAL

jdbc2.testWhileIdle:true

jdbc2.testOnBorrow:false

jdbc2.testOnReturn:false

jdbc2.maxOpenPreparedStatements:20

jdbc2.removeAbandoned:true

jdbc2.removeAbandonedTimeout:180

jdbc2.logAbandoned:true

（二）配置通知与切面

1.配置通知

package com.netease.numen.core.annotation;

import java.lang.annotation.*;

/**

* @author liyan

@Target({ ElementType.PARAMETER, ElementType.METHOD })

@Retention(RetentionPolicy.RUNTIME)

@Documented

public @interface DatabaseConfiguration {

/**

* annotation description

* @return {@link java.lang.String}

String description() default "";

/**

* annotation value ,default value "dataSource"

* @return {@link java.lang.String}

String value() default "";

}

2.配置切面

package com.netease.numen.core.aop;

import java.lang.reflect.Method;

import org.aspectj.lang.JoinPoint;

import org.aspectj.lang.annotation.After;

import org.aspectj.lang.annotation.AfterThrowing;

import org.aspectj.lang.annotation.Aspect;

import org.aspectj.lang.annotation.Before;

import org.aspectj.lang.annotation.Pointcut;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import com.netease.numen.core.annotation.DatabaseConfiguration;

import com.netease.numen.core.util.MultipleDataSource;

/**

* 数据库配置切面

* @author liyan

@Aspect

public class DatabaseConfigurationAspect {

/**

* default dataSource

public static final String DEFAULT_DATASOURCE = "dataSource";

/**

* 日志

private static final Logger LOGGER = LoggerFactory.getLogger(DatabaseConfigurationAspect.class);

@Pointcut("@annotation(com.netease.numen.core.annotation.DatabaseConfiguration)")

public void DBAspect() {

}

/**

* 前置通知

* @param joinPoint 切点

@Before("DBAspect()")

public void doBefore(JoinPoint joinPoint) {

try {

MultipleDataSource.setDataSourceKey(getTargetDataSource(joinPoint));

LOGGER.info("Methods Described:{}", getDescription(joinPoint));

LOGGER.info("Replace DataSource:{}", getTargetDataSource(joinPoint));

} catch (Exception e) {

LOGGER.warn("DataSource Switch Exception:{}", e);

MultipleDataSource.setDataSourceKey(DEFAULT_DATASOURCE);

}

/**

* 异常通知

* @param joinPoint 切点

* @param e 异常

@AfterThrowing(pointcut = "DBAspect()", throwing = "e")

public void doAfterThrowing(JoinPoint joinPoint, Throwable e) {

try {

MultipleDataSource.setDataSourceKey(DEFAULT_DATASOURCE);

} catch (Exception ex) {

LOGGER.warn("DataSource Switch Exception:{}", e);

}

/**

* 方法后通知

* @param joinPoint 切点

@After("DBAspect()")

public void doAfter(JoinPoint joinPoint) {

try {

MultipleDataSource.setDataSourceKey(DEFAULT_DATASOURCE);

LOGGER.info("Restore Default DataSource:{}", DEFAULT_DATASOURCE);

} catch (Exception e) {

LOGGER.warn("Restore Default DataSource Exception:{}", e);

}

/**

* 获取数据源描述

* @param joinPoint 切点

* @return DB-Key(数据库)

* @throws Exception

@SuppressWarnings("rawtypes")

public static String getDescription(JoinPoint joinPoint) throws Exception {

String targetName = joinPoint.getTarget().getClass().getName();

String methodName = joinPoint.getSignature().getName();

Object[] arguments = joinPoint.getArgs();

Class targetClass = Class.forName(targetName);

Method[] methods = targetClass.getMethods();

String description = "";

for (Method method : methods) {

if (method.getName().equals(methodName)) {

Class[] clazzs = method.getParameterTypes();

if (clazzs.length == arguments.length) {

description = method.getAnnotation(DatabaseConfiguration.class).description();

if (description == null || "".equals(description))

description = "Database switch";

break;

}

return description;

}

/**

* 获取数据源

* @param joinPoint 切点

* @return DB-Key(数据库)

* @throws Exception

@SuppressWarnings("rawtypes")

public static String getTargetDataSource(JoinPoint joinPoint) throws Exception {

String targetName = joinPoint.getTarget().getClass().getName();

String methodName = joinPoint.getSignature().getName();

Object[] arguments = joinPoint.getArgs();

Class targetClass = Class.forName(targetName);

Method[] methods = targetClass.getMethods();

String value = "";

for (Method method : methods) {

if (method.getName().equals(methodName)) {

Class[] clazzs = method.getParameterTypes();

if (clazzs.length == arguments.length) {

value = method.getAnnotation(DatabaseConfiguration.class).value();

if (value == null || "".equals(value))

value = DEFAULT_DATASOURCE;

break;

}

return value;

}

（三）编写切换数据源工具类

package com.netease.numen.core.util;

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**

* 多数据源配置

* 说明：定义动态数据源，实现通过集成Spring提供的AbstractRoutingDataSource，只需要

* 实现determineCurrentLookupKey方法即可

* 由于DynamicDataSource是单例的，线程不安全的，所以采用ThreadLocal保证线程安全，由

* DynamicDataSourceHolder完成。

* @author Liyan

public class MultipleDataSource extends AbstractRoutingDataSource {

private static final ThreadLocal<String> dataSourceKey = new InheritableThreadLocal<String>();

public static void setDataSourceKey(String dataSource) {

dataSourceKey.set(dataSource);

}

@Override

protected Object determineCurrentLookupKey() {

// TODO Auto-generated method stub

return dataSourceKey.get();

}

（四）如何使用

这就很简单了，只要在serviceImpl中，要切换数据源前，调用工具类：

public String isExist(String jobNumber) throws DataAccessException {

try {

//切换数据源，对中间库操作

MultipleDataSource.setDataSourceKey("dataSource4");

Map<String, Object> param = new HashMap<String, Object>(0);

param.put("jobNumber", jobNumber);

return mapper.isExist(param);

} catch (DataAccessException e) {

throw e;

} finally{

//切回数据源

MultipleDataSource.setDataSourceKey("dataSource");

}

标签：数据库

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