由于公司业务划分了多个数据库，开发一个项目会同事调用多个库，经过学习我们采用了注解+aop的方式实现的

1.首先定义一个注解类

@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.METHOD)public @interface TargetDataSource { String value();//此处接收的是数据源的名称}

2.然后建一个配置类，这个在项目启动时会加载数据源，一开始采用了HikariCP，查资料说是最快性能最好的，然后又发现了阿里的druid，这个功能比较全面，而且性能也还可以，最主要他还有监控功能，具体实现看如下代码

package com.example.demo.datasource; import com.alibaba.druid.pool.DruidDataSource;import com.alibaba.druid.support.http.StatViewServlet;import com.alibaba.druid.support.http.WebStatFilter;import com.example.demo.datasource.DynamicDataSource;import com.zaxxer.hikari.HikariConfig;import com.zaxxer.hikari.HikariDataSource;import lombok.extern.slf4j.Slf4j;import org.mybatis.spring.annotation.MapperScan;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.beans.factory.annotation.Value;import org.springframework.boot.web.servlet.FilterRegistrationBean;import org.springframework.boot.web.servlet.ServletRegistrationBean;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.jdbc.datasource.DataSourceTransactionManager;import org.springframework.scheduling.annotation.EnableScheduling;import org.springframework.scheduling.annotation.Scheduled;import org.springframework.transaction.PlatformTransactionManager;import org.w3c.dom.NodeList;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.Node; import javax.servlet.annotation.WebInitParam;import javax.servlet.annotation.WebServlet;import javax.sql.DataSource;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import java.lang.reflect.Field;import java.lang.reflect.Method;import java.util.HashMap;import java.util.Map;import java.io.File;import com.alibaba.druid.support.http.StatViewServlet;/** * Author: wangchao * Version： * Date: 2017/9/11 * Description:数据源配置 * Modification History: * Date Author Version Description * -------------------------------------------------------------- * Why & What is modified: */ @Configuration@EnableSchedulingpublic class DataSourceConfig { @Value("${datasource.filePath}") private String filePath;//数据源配置 @Bean(name = "dataSource") public DataSource dataSource() { //按照目标数据源名称和目标数据源对象的映射存放在Map中 Map<Object, Object> targetDataSources = new HashMap<>(); //查找xml数据连接字符串 targetDataSources=getdataMap(filePath); //动态获取DBProperties类申明的属性 //采用是想AbstractRoutingDataSource的对象包装多数据源 DynamicDataSource dataSource = new DynamicDataSource(); dataSource.setTargetDataSources(targetDataSources); //设置默认的数据源，当拿不到数据源时，使用此配置 //dataSource.setDefaultTargetDataSource(properties.getUzaiTravel()); return dataSource; } @Bean public PlatformTransactionManager txManager() { return new DataSourceTransactionManager(dataSource()); } /** *获取数据源集合 */ private Map<Object, Object> getdataMap(String fiePath) { try { Map<Object, Object> targetDataSources = new HashMap<>(); File xmlFile = new File(fiePath); DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); Document doc = builder.parse(xmlFile); doc.getDocumentElement().normalize(); System.out.println("Root element: " + doc.getDocumentElement().getNodeName()); NodeList nList = doc.getElementsByTagName("db"); for(int i = 0 ; i<nList.getLength();i++) { Node node = nList.item(i); Element ele = (Element)node; DruidDataSource dataSource = new DruidDataSource(); dataSource.setDriverClassName(ele.getElementsByTagName("driver-class").item(0).getTextContent()); dataSource.setUsername(ele.getElementsByTagName("username").item(0).getTextContent()); dataSource.setPassword(ele.getElementsByTagName("password").item(0).getTextContent()); dataSource.setUrl(ele.getElementsByTagName("jdbc-url").item(0).getTextContent()); dataSource.setInitialSize(5); dataSource.setMinIdle(1); dataSource.setMaxActive(10);// 启用监控统计功能 dataSource.setFilters("stat");//设置是否显示sql语句 targetDataSources.put(ele.getElementsByTagName("databasename").item(0).getTextContent(), dataSource); } return targetDataSources; } catch (Exception ex) { return null; } } //访问的ip @Value("${druid.IP}") private String IP; //登录名 @Value("${druid.druidLgoinName}") private String druidLgoinName; //密码 @Value("${druid.druidLgoinPassword}") private String druidLgoinPassword; @Bean public ServletRegistrationBean DruidStatViewServle() { //org.springframework.boot.context.embedded.ServletRegistrationBean提供类的进行注册. ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*"); //添加初始化参数：initParams //白名单： servletRegistrationBean.addInitParameter("allow",IP); //IP黑名单 (存在共同时，deny优先于allow) : 如果满足deny的话提示:Sorry, you are not permitted to view this page. // servletRegistrationBean.addInitParameter("deny", "192.168.1.73"); //登录查看信息的账号密码. servletRegistrationBean.addInitParameter("loginUsername",druidLgoinName); servletRegistrationBean.addInitParameter("loginPassword",druidLgoinPassword); //是否能够重置数据. servletRegistrationBean.addInitParameter("resetEnable","false"); return servletRegistrationBean; } /** * 注册一个：filterRegistrationBean * @return */ @Bean public FilterRegistrationBean druidStatFilter2(){ FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter()); //添加过滤规则. filterRegistrationBean.addUrlPatterns("/*"); //添加不需要忽略的格式信息. filterRegistrationBean.addInitParameter("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*"); return filterRegistrationBean; } }

3.动态数据源，从之前已加载的数据源中选取，DynamicDataSource和DynamicDataSourceHolder配合使用

public class DynamicDataSource extends AbstractRoutingDataSource{ //数据源路由，此方用于产生要选取的数据源逻辑名称 @Override protected Object determineCurrentLookupKey() { //从共享线程中获取数据源名称 return DynamicDataSourceHolder.getDataSource(); }}public class DynamicDataSourceHolder { /** * 本地线程共享对象 */ private static final ThreadLocal<String> THREAD_LOCAL = new ThreadLocal<>(); public static void putDataSource(String name) { THREAD_LOCAL.set(name); } public static String getDataSource() { return THREAD_LOCAL.get(); } public static void removeDataSource() { THREAD_LOCAL.remove(); }}

4.就是使用aop，在dao层切换数据源

@Component@Aspectpublic class DataSourceAspect { //切换放在mapper接口的方法上，所以这里要配置AOP切面的切入点 @Pointcut("execution( * com.example.demo.dao.*.*(..))") public void dataSourcePointCut() { } @Before("dataSourcePointCut()") public void before(JoinPoint joinPoint) { Object target = joinPoint.getTarget(); String method = joinPoint.getSignature().getName(); Class<?>[] clazz = target.getClass().getInterfaces(); Class<?>[] parameterTypes = ((MethodSignature) joinPoint.getSignature()).getMethod().getParameterTypes(); try { Method m = clazz[0].getMethod(method, parameterTypes); //如果方法上存在切换数据源的注解，则根据注解内容进行数据源切换 if (m != null && m.isAnnotationPresent(TargetDataSource.class)) { TargetDataSource data = m.getAnnotation(TargetDataSource.class); String dataSourceName = data.value(); DynamicDataSourceHolder.putDataSource(dataSourceName); } else { } } catch (Exception e) { } } //执行完切面后，将线程共享中的数据源名称清空 @After("dataSourcePointCut()") public void after(JoinPoint joinPoint){ DynamicDataSourceHolder.removeDataSource(); }}

数据连接都配置在xml里面

xml路径在配置文件里面配置，这样适用读写分离和多个不同的数据源，而且多个项目可以共用这一个配置

最后引用注解，需要注意的是注解的数据库名称和xml里面databasename节点是一一对应的，可以随便自定义，比如读写是一个数据库名字，这时候就可以定义成pringtest_r表示读库

至此多数据源就配置完成，至于阿里的druid下次再分享，代码都贴出来，如果大家感觉还有哪些不足的地方，欢迎指正。

以上这篇spring boot+mybatis 多数据源切换(实例讲解)就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。