Springboot之多数据源的配置使用
- 2019 年 10 月 8 日
- 笔记
引入
现在的企业服务逐渐地呈现出数据的指数级增长趋势，无论从数据库的选型还是搭建，大多数的团队都开始考虑多样化的数据库来支撑存储服务。例如分布式数据库、Nosql数据库、内存数据库、关系型数据库等等。再到后端开发来说，服务的增多，必定需要考虑到多数据源的切换使用来兼容服务之间的调用。为解决这一难题，今天就来分享一个关于多数据源的切换使用配置。
使用前提：
- JDK8+
- Springboot
- IDEA
- Mysql5.5+
- lombok
02
具体配置
使用spring AOP的思想，在进入orm之前，进行DataSource的Type切换。 添加maven依赖,我使用的是springboot-2.0.5版本。
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-aop</artifactId> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.10</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency>
创建application.yml
server: port: 8080 spring: profiles: active: dev application: name: @pom.artifactId@ jpa: generate-ddl: false show-sql: true hibernate: ddl-auto: none datasource: default: url: jdbc:mysql://localhost:3306/bboyhan?characterEncoding=UTF-8&useUnicode=true&useSSL=false username: root password: root driver: com.mysql.jdbc.Driver type: com.alibaba.druid.pool.DruidDataSource names: tb1,tb2 tb1: url: jdbc:mysql://localhost:3306/tb1?characterEncoding=UTF-8&useUnicode=true&useSSL=false username: root password: root driver: com.mysql.jdbc.Driver tb2: url: jdbc:mysql://localhost:3306/tb2?characterEncoding=UTF-8&useUnicode=true&useSSL=false username: root password: root driver: com.mysql.jdbc.Driver
创建注解类@DbName
import java.lang.annotation.*; /** * @Auther: bboyHan * @Date: 2019/1/22 18:12 * @Description: */ @Target({ElementType.TYPE, ElementType.METHOD}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface DbName { String value(); }
创建aop切面类ChooseDbAspect
import com.jkzx.common.annotation.DbName; import com.jkzx.common.config.dbsource.DynamicDataSourceContextHolder; import lombok.extern.slf4j.Slf4j; 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.core.annotation.Order; import org.springframework.stereotype.Component; /** * @Auther: bboyHan * @Date: 2019/1/22 18:13 * @Description: */ @Component @Order(-1)//保证在@Transactional之前执行 @Aspect @Slf4j public class ChooseDbAspect { @Pointcut("@annotation(com.bboyhan.annotation.DbName)") public void chooseDbPointCut(){} //改变数据源 @Before("@annotation(dbName)") public void changeDataSource(JoinPoint joinPoint, DbName dbName) { String dbid = dbName.value(); if (!DynamicDataSourceContextHolder.isContainsDataSource(dbid)) { //joinPoint.getSignature() ：获取连接点的方法签名对象 log.error("数据源 " + dbid + " 不存在使用默认的数据源 -> " + joinPoint.getSignature()); } else { log.debug("使用数据源：" + dbid); DynamicDataSourceContextHolder.setDataSourceType(dbid); } } @After("@annotation(dbName)") public void clearDataSource(JoinPoint joinPoint, DbName dbName) { log.debug("清除数据源 " + dbName.value() + " ! - start"); DynamicDataSourceContextHolder.clearDataSourceType(); } }
使用ThreadLocal创建一个线程安全的类
import lombok.extern.slf4j.Slf4j; import java.util.ArrayList; import java.util.List; /** * @Auther: bboyHan * @Date: 2019/1/22 18:13 * @Description: */ @Slf4j public class DynamicDataSourceContextHolder { //存放当前线程使用的数据源类型信息 private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>(); //存放数据源id public static List<String> dataSourceIds = new ArrayList<String>(); //设置数据源 public static void setDataSourceType(String dataSourceType) { contextHolder.set(dataSourceType); } //获取数据源 public static String getDataSourceType() { return contextHolder.get(); } //清除数据源 public static void clearDataSourceType() { contextHolder.remove(); log.info("清除数据源:{}", contextHolder.get() + " - end"); } //判断当前数据源是否存在 public static boolean isContainsDataSource(String dataSourceId) { return dataSourceIds.contains(dataSourceId); } }
创建一个Register实现ImportBeanDefinitionRegistrar, EnvironmentAware
import lombok.extern.slf4j.Slf4j; import org.springframework.beans.MutablePropertyValues; import org.springframework.beans.factory.support.BeanDefinitionRegistry; import org.springframework.beans.factory.support.GenericBeanDefinition; import org.springframework.boot.jdbc.DataSourceBuilder; import org.springframework.context.EnvironmentAware; import org.springframework.context.annotation.ImportBeanDefinitionRegistrar; import org.springframework.core.env.Environment; import org.springframework.core.type.AnnotationMetadata; import javax.sql.DataSource; import java.util.HashMap; import java.util.Map; /** * @Auther: bboyHan * @Date: 2019/1/22 18:19 * @Description: */ @Slf4j public class DynamicDataSourceRegister implements ImportBeanDefinitionRegistrar, EnvironmentAware { //指定默认数据源(springboot2.0默认数据源是hikari，在这里我使用DruidDataSource) private static final String DATASOURCE_TYPE_DEFAULT = "com.alibaba.druid.pool.DruidDataSource"; //默认数据源 private DataSource defaultDataSource; //用户自定义数据源 private Map<String, DataSource> slaveDataSources = new HashMap<>(); @Override public void setEnvironment(Environment environment) { initDefaultDataSource(environment); initMutilDataSources(environment); } private void initDefaultDataSource(Environment env) { // 读取主数据源,解析yml文件 Map<String, Object> dsMap = new HashMap<>(); dsMap.put("driver", env.getProperty("spring.datasource.default.driver")); dsMap.put("url", env.getProperty("spring.datasource.default.url")); dsMap.put("username", env.getProperty("spring.datasource.default.username")); dsMap.put("password", env.getProperty("spring.datasource.default.password")); dsMap.put("type", env.getProperty("spring.datasource.default.type")); defaultDataSource = buildDataSource(dsMap); } private void initMutilDataSources(Environment env) { // 读取配置文件获取更多数据源 String dsPrefixs = env.getProperty("spring.datasource.names"); for (String dsPrefix : dsPrefixs.split(",")) { // 多个数据源 Map<String, Object> dsMap = new HashMap<>(); dsMap.put("driver", env.getProperty("spring.datasource." + dsPrefix + ".driver")); dsMap.put("url", env.getProperty("spring.datasource." + dsPrefix + ".url")); dsMap.put("username", env.getProperty("spring.datasource." + dsPrefix + ".username")); dsMap.put("password", env.getProperty("spring.datasource." + dsPrefix + ".password")); DataSource ds = buildDataSource(dsMap); slaveDataSources.put(dsPrefix, ds); } } @Override public void registerBeanDefinitions(AnnotationMetadata annotationMetadata, BeanDefinitionRegistry beanDefinitionRegistry) { Map<Object, Object> targetDataSources = new HashMap<Object, Object>(); //添加默认数据源 targetDataSources.put("dataSource", this.defaultDataSource); DynamicDataSourceContextHolder.dataSourceIds.add("dataSource"); //添加其他数据源 targetDataSources.putAll(slaveDataSources); DynamicDataSourceContextHolder.dataSourceIds.addAll(slaveDataSources.keySet()); //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); //注册 - BeanDefinitionRegistry beanDefinitionRegistry.registerBeanDefinition("dataSource", beanDefinition); log.info("Dynamic DataSource Registry"); } public DataSource buildDataSource(Map<String, Object> dataSourceMap) { try { Object type = dataSourceMap.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 = dataSourceMap.get("driver").toString(); String url = dataSourceMap.get("url").toString(); String username = dataSourceMap.get("username").toString(); String password = dataSourceMap.get("password").toString(); // 自定义DataSource配置 DataSourceBuilder factory = DataSourceBuilder.create().driverClassName(driverClassName).url(url) .username(username).password(password).type(dataSourceType); return factory.build(); } catch (ClassNotFoundException e) { e.printStackTrace(); } return null; } }
创建一个DynamicDataSource重写AbstractRoutingDataSource的determineCurrentLookupKey()方法
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource; /** * @Auther: bboyHan * @Date: 2019/1/22 18:20 * @Description: */ public class DynamicDataSource extends AbstractRoutingDataSource { @Override protected Object determineCurrentLookupKey() { return DynamicDataSourceContextHolder.getDataSourceType(); } }
0
3
测试
略，如果不明白的地方，可以识别文末二维码加小编咨询。
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