一、Springboot 动态数据源

把文章下半部分的代码复制到项目包中，然后按下面步骤处理就能实现多数据源的切换。

1、启动类注册动态数据源

@SpringBootApplication @Import({DynamicDataSourceRegister.class}) public class SpringBootSampleApplication {}

2、配置文件application.properties

#JDBC配置 #默认数据源 #spring.datasource.type=com.alibaba.druid.pool.DruidDataSource type可以修改连接池，默认采用Tomcat的连接池 spring.datasource.url=jdbc:mysql://localhost:3306/consult spring.datasource.username=myConsult spring.datasource.password=123456 spring.datasource.driver-class-name=org.gjt.mm.mysql.Driver # 更多数据源  custom.datasource.names=ds1,ds2 custom.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver custom.datasource.ds1.url=jdbc:mysql://localhost:3306/test1 custom.datasource.ds1.username=root custom.datasource.ds1.password=123456 custom.datasource.ds2.driver-class-name=com.mysql.jdbc.Driver custom.datasource.ds2.url=jdbc:mysql://localhost:3306/test2 custom.datasource.ds2.username=root custom.datasource.ds2.password=123456

3、配置文件中加上配置

mybatis.typeAliasesPackage=com.dongnao.jack.bean mybatis.mapperLocations=classpath:com/dongnao/jack/xml/*Mapper.xml

补充：mybatis引入后mapper的映射接口不用添加注解，其他用法一样。

4、动态切换数据源

使用时用@TargetDataSource(name = “ds1”)指明数据源即可。

@TargetDataSource(name = "ds1") public User findUserByName(String username) { List<User> users = userMapper.findByUserName(username); return users.size() > 0 ? users.get(0) : null; } @Transactional @TargetDataSource(name = "ds2") public int saveArea(ConsultConfigArea area) { int cout = mapper.saveArea(area); // throw new RuntimeException(); return cout; }

下面贴上完整的处理代码：

1、DynamicDataSourceRegister

package com.dongnao.jack.dynamicDataSource; import java.util.HashMap; import java.util.Map; import javax.sql.DataSource; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.MutablePropertyValues; import org.springframework.beans.PropertyValues; import org.springframework.beans.factory.support.BeanDefinitionRegistry; import org.springframework.beans.factory.support.GenericBeanDefinition; import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder; import org.springframework.boot.bind.RelaxedDataBinder; import org.springframework.boot.bind.RelaxedPropertyResolver; import org.springframework.context.EnvironmentAware; import org.springframework.context.annotation.ImportBeanDefinitionRegistrar; import org.springframework.core.convert.ConversionService; import org.springframework.core.convert.support.DefaultConversionService; import org.springframework.core.env.Environment; import org.springframework.core.type.AnnotationMetadata; public class DynamicDataSourceRegister implements ImportBeanDefinitionRegistrar, EnvironmentAware { private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceRegister.class); private ConversionService conversionService = new DefaultConversionService(); private PropertyValues dataSourcePropertyValues; // 如配置文件中未指定数据源类型，使用该默认值 private static final Object DATASOURCE_TYPE_DEFAULT = "org.apache.tomcat.jdbc.pool.DataSource"; // private static final Object DATASOURCE_TYPE_DEFAULT = // "com.zaxxer.hikari.HikariDataSource"; // 数据源 private DataSource defaultDataSource; private Map<String, DataSource> customDataSources = new HashMap<String, DataSource>(); public void registerBeanDefinitions( AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) { Map<Object, Object> targetDataSources = new HashMap<Object, Object>(); // 将主数据源添加到更多数据源中 targetDataSources.put("dataSource", defaultDataSource); DynamicDataSourceContextHolder.dataSourceIds.add("dataSource"); // 添加更多数据源 targetDataSources.putAll(customDataSources); for (String key : customDataSources.keySet()) { DynamicDataSourceContextHolder.dataSourceIds.add(key); } // 创建DynamicDataSource GenericBeanDefinition beanDefinition = new GenericBeanDefinition(); beanDefinition.setBeanClass(DynamicDataSource.class); beanDefinition.setSynthetic(true); MutablePropertyValues mpv = beanDefinition.getPropertyValues(); mpv.addPropertyValue("defaultTargetDataSource", defaultDataSource); mpv.addPropertyValue("targetDataSources", targetDataSources); registry.registerBeanDefinition("dataSource", beanDefinition); logger.info("Dynamic DataSource Registry"); } /** * 创建DataSource * * @param type * @param driverClassName * @param url * @param username * @param password * @return * @author SHANHY * @create 2016年1月24日 */ @SuppressWarnings("unchecked") public DataSource buildDataSource(Map<String, Object> dsMap) { try { Object type = dsMap.get("type"); if (type == null) type = DATASOURCE_TYPE_DEFAULT;// 默认DataSource Class<? extends DataSource> dataSourceType; dataSourceType = (Class<? extends DataSource>)Class.forName((String)type); String driverClassName = dsMap.get("driver-class-name").toString(); String url = dsMap.get("url").toString(); String username = dsMap.get("username").toString(); String password = dsMap.get("password").toString(); DataSourceBuilder factory = DataSourceBuilder.create() .driverClassName(driverClassName) .url(url) .username(username) .password(password) .type(dataSourceType); return factory.build(); } catch (ClassNotFoundException e) { e.printStackTrace(); } return null; } /** * 加载多数据源配置 */ public void setEnvironment(Environment env) { initDefaultDataSource(env); initCustomDataSources(env); } /** * 初始化主数据源 * * @author SHANHY * @create 2016年1月24日 */ private void initDefaultDataSource(Environment env) { // 读取主数据源 RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver( env, "spring.datasource."); Map<String, Object> dsMap = new HashMap<String, Object>(); dsMap.put("type", propertyResolver.getProperty("type")); dsMap.put("driver-class-name", propertyResolver.getProperty("driver-class-name")); dsMap.put("url", propertyResolver.getProperty("url")); dsMap.put("username", propertyResolver.getProperty("username")); dsMap.put("password", propertyResolver.getProperty("password")); defaultDataSource = buildDataSource(dsMap); dataBinder(defaultDataSource, env); } /** * 为DataSource绑定更多数据 * * @param dataSource * @param env * @author SHANHY * @create 2016年1月25日 */ private void dataBinder(DataSource dataSource, Environment env) { RelaxedDataBinder dataBinder = new RelaxedDataBinder(dataSource); //dataBinder.setValidator(new LocalValidatorFactory().run(this.applicationContext)); dataBinder.setConversionService(conversionService); dataBinder.setIgnoreNestedProperties(false);//false dataBinder.setIgnoreInvalidFields(false);//false dataBinder.setIgnoreUnknownFields(true);//true if (dataSourcePropertyValues == null) { Map<String, Object> rpr = new RelaxedPropertyResolver(env, "spring.datasource").getSubProperties("."); Map<String, Object> values = new HashMap<String, Object>(rpr); // 排除已经设置的属性 values.remove("type"); values.remove("driver-class-name"); values.remove("url"); values.remove("username"); values.remove("password"); dataSourcePropertyValues = new MutablePropertyValues(values); } dataBinder.bind(dataSourcePropertyValues); } /** * 初始化更多数据源 * * @author SHANHY * @create 2016年1月24日 */ private void initCustomDataSources(Environment env) { // 读取配置文件获取更多数据源，也可以通过defaultDataSource读取数据库获取更多数据源 RelaxedPropertyResolver propertyResolver = new RelaxedPropertyResolver( env, "custom.datasource."); String dsPrefixs = propertyResolver.getProperty("names"); for (String dsPrefix : dsPrefixs.split(",")) {// 多个数据源 Map<String, Object> dsMap = propertyResolver.getSubProperties(dsPrefix + "."); DataSource ds = buildDataSource(dsMap); customDataSources.put(dsPrefix, ds); dataBinder(ds, env); } } }

2、TargetDataSource

package com.dongnao.jack.dynamicDataSource; import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; @Target({ElementType.METHOD, ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface TargetDataSource { String name(); }

3、DynamicDataSource

package com.dongnao.jack.dynamicDataSource; import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource; public class DynamicDataSource extends AbstractRoutingDataSource { @Override protected Object determineCurrentLookupKey() { // TODO Auto-generated method stub return DynamicDataSourceContextHolder.getDataSourceType(); } }

4、DynamicDataSourceAspect

package com.dongnao.jack.dynamicDataSource; 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.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.core.annotation.Order; import org.springframework.stereotype.Component; @Aspect //保证该AOP在@Transactional之前执行 @Order(-1) @Component public class DynamicDataSourceAspect { private static final Logger logger = LoggerFactory.getLogger(DynamicDataSourceAspect.class); /** * @Description 在方法执行之前执行  @annotation(ds) 会拦截有ds这个注解的方法即有 TargetDataSource这个注解的 * @param @param point * @param @param ds * @param @throws Throwable 参数 * @return void 返回类型 * @throws */ @Before("@annotation(ds)") public void changeDataSource(JoinPoint point, TargetDataSource ds) throws Throwable { String dsId = ds.name(); if (!DynamicDataSourceContextHolder.containsDataSource(dsId)) { logger.error("数据源[{}]不存在，使用默认数据源 > {}", ds.name(), point.getSignature()); } else { logger.debug("Use DataSource : {} > {}", ds.name(), point.getSignature()); DynamicDataSourceContextHolder.setDataSourceType(ds.name()); } } /** * @Description 在方法执行之后执行  @annotation(ds) 会拦截有ds这个注解的方法即有 TargetDataSource这个注解的 * @param @param point * @param @param ds 参数 * @return void 返回类型 * @throws */ @After("@annotation(ds)") public void restoreDataSource(JoinPoint point, TargetDataSource ds) { logger.debug("Revert DataSource : {} > {}", ds.name(), point.getSignature()); DynamicDataSourceContextHolder.clearDataSourceType(); } }

5、DynamicDataSourceContextHolder

package com.dongnao.jack.dynamicDataSource; import java.util.ArrayList; import java.util.List; public class DynamicDataSourceContextHolder { private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>(); public static List<String> dataSourceIds = new ArrayList<String>(); public static void setDataSourceType(String dataSourceType) { contextHolder.set(dataSourceType); } public static String getDataSourceType() { return contextHolder.get(); } public static void clearDataSourceType() { contextHolder.remove(); } /** * 判断指定DataSrouce当前是否存在 * * @param dataSourceId * @return * @author SHANHY * @create 2016年1月24日 */ public static boolean containsDataSource(String dataSourceId) { return dataSourceIds.contains(dataSourceId); } }