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
classpath:*.properties
classpath:/mybatis/mapper/*.xml
2.配置jdbc.properties
#------------------------JDBC-------------------------------jdbc.url:jdbc:sqlserver://ip地址1:端口;database=数据库;integratedSecurity=falsejdbc.driverClassName:com.microsoft.sqlserver.jdbc.SQLServerDriverjdbc.username:用户名jdbc.password:密码jdbc.filters:statjdbc.maxActive:10jdbc.initialSize:2jdbc.maxWait:60000jdbc.minIdle:2jdbc.timeBetweenEvictionRunsMillis:60000jdbc.minEvictableIdleTimeMillis:300000jdbc.validationQuery:SELECT 'x' FROM DUALjdbc.testWhileIdle:truejdbc.testOnBorrow:falsejdbc.testOnReturn:falsejdbc.maxOpenPreparedStatements:20jdbc.removeAbandoned:truejdbc.removeAbandonedTimeout:180jdbc.logAbandoned:true #---------------------------JDBC-2----------------------------jdbc2.url:jdbc:mysql://ip地址1:端口/数据库?autoReconnect=truejdbc2.driverClassName:com.mysql.jdbc.Driverjdbc2.username:用户名jdbc2.password:密码jdbc2.filters:statjdbc2.maxActive:10jdbc2.initialSize:2jdbc2.maxWait:60000jdbc2.minIdle:2jdbc2.timeBetweenEvictionRunsMillis:60000jdbc2.minEvictableIdleTimeMillis:300000jdbc2.validationQuery:SELECT 'x' FROM DUALjdbc2.testWhileIdle:truejdbc2.testOnBorrow:falsejdbc2.testOnReturn:falsejdbc2.maxOpenPreparedStatements:20jdbc2.removeAbandoned:truejdbc2.removeAbandonedTimeout:180jdbc2.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)@Documentedpublic @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 */@Aspectpublic 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 dataSourceKey = new InheritableThreadLocal (); 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 param = new HashMap (0); param.put("jobNumber", jobNumber); return mapper.isExist(param); } catch (DataAccessException e) { throw e; } finally{ //切回数据源 MultipleDataSource.setDataSourceKey("dataSource"); } }