1：yml 配置

spring:datasource:dynamic:datasource:master:url: jdbc:mysql://192.168.11.50:3306/dsdd?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=UTCusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driversecond-datasource:url: jdbc:mysql://192.168.11.50:3306/commons_utils?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=UTCusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driver

2：必须pom依赖配

        <!-- 动态数据源 --><dependency><groupId>com.baomidou</groupId><artifactId>dynamic-datasource-spring-boot-starter</artifactId><version>3.2.0</version></dependency>

2-1：不要加入一下依赖不然会报以下错误

        <dependency><groupId>com.h2database</groupId><artifactId>h2</artifactId><version>1.4.200</version><scope>runtime</scope></dependency><!-- druid --><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.6</version></dependency>

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2-2：当出现以上错误可以在yml配置文件去掉DruidDataSourceAutoConfigure，如下

spring:autoconfigure:exclude: com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure

3：加入数据库连接池druid依赖管理(使用多数据源一定要用链接池)，Druid是阿里巴巴开源的一个数据库连接池和实时数据分析组件。相比其他连接池，Druid在功能特性、性能、监控等方面有很多优势，比如支持SQL解析、慢SQL日志、提供多维度监控等

spring:autoconfigure:exclude: com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfiguredatasource:druid:stat-view-servlet:enabled: trueloginUsername: adminloginPassword: 123456allow:web-stat-filter:enabled: truedynamic:druid: # 全局druid参数，绝大部分值和默认保持一致。(现已支持的参数如下,不清楚含义不要乱设置)# 连接池的配置信息# 初始化大小，最小，最大initial-size: 5min-idle: 5maxActive: 20# 配置获取连接等待超时的时间rmaxWait: 60000# 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timeBetweenEvictionRunsMillis: 60000# 配置一个连接在池中最小生存的时间，单位是毫秒minEvictableIdleTimeMillis: 300000validationQuery: SELECT 1 FROM DUALtestWhileIdle: truetestOnBorrow: falsetestOnReturn: false# 打开PSCache，并且指定每个连接上PSCache的大小poolPreparedStatements: truemaxPoolPreparedStatementPerConnectionSize: 20# 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙filters: stat,wall,slf4j# 通过connectProperties属性来打开mergeSql功能；慢SQL记录connectionProperties: druid.stat.mergeSql\=true;druid.stat.slowSqlMillis\=5000datasource:master:url: jdbc:mysql://192.168.11.50:3306/dsdd?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=UTCusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driversecond:url: jdbc:mysql://192.168.11.50:3306/commons_utils?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=UTCusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driver

3-1：加入依赖

        <!-- 动态数据源 --><dependency><groupId>com.baomidou</groupId><artifactId>dynamic-datasource-spring-boot-starter</artifactId><version>3.2.0</version></dependency><!-- druid --><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.6</version></dependency>

Druid连接池的自动配置类是DruidDataSourceAutoConfigure类上有一行注解

@EnableConfigurationProperties({DruidStatProperties.class, DataSourceProperties.class})

@EnableConfigurationProperties注解的作用是：使配置文件中的配置生效并且映射到指定类的属性

DruidStatProperties：指定的前缀是spring.datasource.druid，主要设置连接池的一些参数

DataSourceProperties：指定的前缀是spring.datasource，主要设置url，username，password等信息

3-2：DruidConfig 配置类

package com.example.poi.config;import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure;
import com.alibaba.druid.spring.boot.autoconfigure.properties.DruidStatProperties;
import com.alibaba.druid.util.Utils;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;import javax.servlet.*;
import java.io.IOException;/*** @Description: DruidConfig配置类*/
@Configuration
@AutoConfigureAfter(DruidDataSourceAutoConfigure.class)
public class DruidConfig {/*** 带有广告的common.js全路径，druid-1.1.14*/private static final String FILE_PATH = "support/http/resources/js/common.js";/*** 原始脚本，触发构建广告的语句*/private static final String ORIGIN_JS = "this.buildFooter();";/*** 替换后的脚本*/private static final String NEW_JS = "//this.buildFooter();";/*** 去除Druid监控页面的广告** @param properties DruidStatProperties属性集合* @return {@link FilterRegistrationBean}*/@Bean@ConditionalOnWebApplication@ConditionalOnProperty(name = "spring.datasource.druid.stat-view-servlet.enabled", havingValue = "true")public FilterRegistrationBean<RemoveAdFilter> removeDruidAdFilter(DruidStatProperties properties) throws IOException {// 获取web监控页面的参数DruidStatProperties.StatViewServlet config = properties.getStatViewServlet();// 提取common.js的配置路径String pattern = config.getUrlPattern() != null ? config.getUrlPattern() : "/druid/*";String commonJsPattern = pattern.replaceAll("\\*", "js/common.js");// 获取common.jsString text = Utils.readFromResource(FILE_PATH);// 屏蔽 this.buildFooter(); 不构建广告final String newJs = text.replace(ORIGIN_JS, NEW_JS);FilterRegistrationBean<RemoveAdFilter> registration = new FilterRegistrationBean<>();registration.setFilter(new RemoveAdFilter(newJs));registration.addUrlPatterns(commonJsPattern);return registration;}/*** 删除druid的广告过滤器** @author BBF*/private class RemoveAdFilter implements Filter {private final String newJs;public RemoveAdFilter(String newJs) {this.newJs = newJs;}@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)throws IOException, ServletException {chain.doFilter(request, response);// 重置缓冲区，响应头不会被重置response.resetBuffer();response.getWriter().write(newJs);}}
}

4：配置动态数据源方法二，yml随意配置或者通过配置类生成数据库链接

4-1：yml配置(记得配置数据库链接池)

datasource:master:url: jdbc:mysql://192.168.11.50:3306/dsdd?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=UTCusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driversecond:url: jdbc:mysql://192.168.11.50:3306/commons_utils?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=UTCusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driver

4-2：配置动态源数据类

@Configuration
public class DatabaseConfig {@Value("${datasource.master.url}")private String dataSourceUrl;@Value("${datasource.master.username}")private String dataSourceUsername;@Value("${datasource.master.password}")private String dataSourcePassword;@Value("${datasource.master.driver-class-name}")private String dataSourceDriverClassName;@Value("${datasource.second.url}")private String dataSourceUrl2;@Value("${datasource.second.username}")private String dataSourceUsername2;@Value("${datasource.second.password}")private String dataSourcePassword2;@Value("${datasource.second.driver-class-name}")private String dataSourceDriverClassName2;public DataSource dataSource() {return  DataSourceBuilder.create().url(dataSourceUrl).username(dataSourceUsername).password(dataSourcePassword).driverClassName("com.mysql.cj.jdbc.Driver").build();}public DataSource dataSource2() {return DataSourceBuilder.create().url(dataSourceUrl2).username(dataSourceUsername2).password(dataSourcePassword2).driverClassName("com.mysql.cj.jdbc.Driver").build();}// 添加动态数据源@Beanpublic DynamicRoutingDataSource dynamicDataSource() {DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource();dynamicRoutingDataSource.addDataSource("master", dataSource());dynamicRoutingDataSource.addDataSource("two", dataSource2());return dynamicRoutingDataSource;}
}

4-3：在server服务层通过@DS调用

    @Override@DS("two")public List<EntityDemo> testSql(Page<EntityDemo> pageList, String id)  {List<EntityDemo> entityDemos = entityDemoMapper.testSql(pageList, id);DynamicDataSourceContextHolder.clear();return entityDemos;

4-4：可以在启动类观察动态数据源情况如下：run.getBean(DataSource.class).getConnection();

@SpringBootApplication
@MapperScan(basePackages = "com.example.poi.mapper")
public class PoiApplication {public static void main(String[] args) {ConfigurableApplicationContext run = SpringApplication.run(PoiApplication.class, args);// 检查数据库连接是否正常try {// 获取DataSource bean，并调用getConnection()方法测试连接run.getBean(javax.sql.DataSource.class).getConnection();System.out.println("数据库连接正常！");} catch (Exception e) {System.err.println("数据库连接异常：" + e.getMessage());// 处理连接异常的逻辑}}
}

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5：方法三配置动态数据源使，使用注解的方式(推荐使用)

5-1：yml配置

spring:datasource:master:jdbcUrl: jdbc:mysql://192.168.11.50:3306/dsdd?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=UTCusername: rootpassword: rootdriver-class-name: com.mysql.cj.jdbc.Driversecond:jdbcUrl: jdbc:mysql://192.168.11.50:3306/commons_utils?characterEncoding=UTF-8&useUnicode=true&useSSL=false&tinyInt1isBit=false&allowPublicKeyRetrieval=true&serverTimezone=UTCusername: rootpassword: rootdriverClassName: com.mysql.cj.jdbc.Driverdruid:#连接池初始化时创建的数据库连接数量initial-size: 10#连接池中保持最小的空闲连接数量。如果空闲连接数量少于这个值，连接池会创建新的连接来补充min-idle: 5#max-active: 80#配置获取链接等待超时的时间max-wait:type: com.alibaba.druid.pool.DruidDataSource

5-2：配置动态源数据类（在需要切换的地方使用@DS就可以），整合mybatis-plus的过程中，我们还需要创建动态数据源的SqlSessionFactory，如果我们想要实现动态数据源切换，则需要手动配置SqlSessionFactory，以便于它使用动态数据源，同理事务管理器也需要重新配置：

@Configuration
public class DatabaseConfig {@Bean("one")@ConfigurationProperties(prefix = "spring.datasource.master")public DataSource dataSource() {return DataSourceBuilder.create().build();}@Bean("two")@ConfigurationProperties(prefix = "spring.datasource.second")public DataSource dataSource2() {return DataSourceBuilder.create().build();}//添加动态数据源@Beanpublic DynamicRoutingDataSource dynamicDataSource(@Qualifier("one") DataSource dataSource, @Qualifier("two") DataSource dataSource2) {DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource();dynamicRoutingDataSource.addDataSource("master", dataSource);dynamicRoutingDataSource.addDataSource("two", dataSource2);return dynamicRoutingDataSource;}@Bean("sqlSessionFactory")public SqlSessionFactory sqlSessionFactoryBean(DynamicRoutingDataSource dynamicRoutingDataSource) throws Exception {//使用SqlSessionFactoryBean不可以正常使用 BaseMapper的MyBatis通用的CRUD//SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();MybatisSqlSessionFactoryBean sessionFactory = new MybatisSqlSessionFactoryBean();sessionFactory.setDataSource(dynamicRoutingDataSource);return sqlSessionFactoryBean.getObject();}/*** 重写事务管理器，管理动态数据源*/@Primary@Bean(value = "transactionManager")public PlatformTransactionManager annotationDrivenTransactionManager(DynamicRoutingDataSource dataSource) {return new DataSourceTransactionManager(dataSource);}
}

5-3：切换使用数据源

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6：方法四配置动态数据源使用，使用注解的方式(推荐使用)

6-1：添加注解和切面

package com.example.poi.minds.annotation;import java.lang.annotation.*;/*** @Author xu* @create 2023/9/7 22*/
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface MinDS {/*** groupName or specific database name or spring SPEL name.** @return the database you want to switch*/String value() default "";
}

package com.example.poi.minds.aop;import com.baomidou.dynamic.datasource.toolkit.DynamicDataSourceContextHolder;
import com.example.poi.config.DataSourceHolder;
import com.example.poi.desensitization.annotation.SensitiveDecode;
import com.example.poi.desensitization.annotation.SensitiveEncode;
import com.example.poi.desensitization.utils.SensitiveInfoUtil;
import com.example.poi.minds.annotation.MinDS;
import lombok.extern.slf4j.Slf4j;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.lang.StringUtils;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;import java.lang.reflect.Method;
import java.util.List;/*** @Author xu* @create 2023/9/7 22*/
@Slf4j
@Aspect
@Component
public class MinDSAspect {/*** 定义切点Pointcut*/@Pointcut("@annotation(com.example.poi.minds.annotation.MinDS) ")public void dsPointCut() {}@Around("dsPointCut()")public Object around(ProceedingJoinPoint joinPoint) throws Throwable {// 处理结果MethodSignature signature = (MethodSignature) joinPoint.getSignature();Method method = signature.getMethod();MinDS minDS = method.getAnnotation(MinDS.class);String value = minDS.value();if (StringUtils.isBlank(value)) {return null;}DataSourceHolder.setDataSource(value);try {return joinPoint.proceed();} finally {DataSourceHolder.clearDataSource();}}
}

在这里插入图片描述

6-2：动态数据源简单的说就是能够自由切换的数据源，Spring提供了一个抽象类AbstractRoutingDataSource，我们只需要extends ，并且重写determineCurrentLookupKey()即可determineCurrentLookupKey()的作用：返回需要切换的数据源的key，然后根据这个key获取对应的数据源信息

package com.example.poi.config;import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;/*** @Author xu* @create 2023/9/7 22*/
public class DynamicDataSource extends AbstractRoutingDataSource {/*** 返回需要使用的数据源key，将会按照这个key从Map中获取对应的数据源（切换）* @return*/@Overrideprotected Object determineCurrentLookupKey() {//从ThreadLocal中取出keyreturn DataSourceHolder.getDataSource();}}

6-3：单独封装一个类：DataSourceHolder，在多线程的情况下，数据源切换如何保证线程隔离呢？，我们不能这边切换了影响了其他线程的执行，这里我们便想到了ThreadLocal

package com.example.poi.config;/*** @Author xu* @create 2023/9/7 20*/
/*** 线程安全类：使用ThreadLocal存储切换数据源后的KEY*/
public class DataSourceHolder {/*** 线程ThreadLocal*/private static final ThreadLocal<String> dataSources = new InheritableThreadLocal();/*** 设置数据源* @param datasource*/public static void setDataSource(String datasource) {dataSources.set(datasource);}/*** 获取数据源* @return*/public static String getDataSource() {return dataSources.get();}/*** 清除数据源*/public static void clearDataSource() {dataSources.remove();}}