本篇内容主要讲解“怎么用SpringBoot + Mybatis多数据源配置实现读写分离”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习“怎么用SpringBoot + Mybatis多数据源配置实现读写分离”吧!
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应用场景：项目中有一些报表统计与查询功能，对数据实时性要求不高，因此考虑对报表的统计与查询去操作slave db，减少对master的压力。
根据网上多份资料测试发现总是使用master数据源，无法切换到slave，经过多次调试修改现已完美通过，现整理下详细步骤和完整代码如下：
实现方式：配置多个数据源，使用Spring AOP实现拦截注解实现数据源的动态切换。
1. application.yml数据库配置：
druid: type: com.alibaba.druid.pool.DruidDataSource master: url: jdbc:MySQL://127.0.0.1:3306/test?characterEncoding=UTF-8&autoReconnect=true&zeroDateTimeBehavior=convertToNull&useUnicode=true driver-class-name: com.mysql.jdbc.Driver username: test password: 123 initial-size: 5 max-active: 10 min-idle: 5 max-wait: 60000 time-between-eviction-runs-millis: 3000 min-evictable-idle-time-millis: 300000 validation-query: SELECT 'x' FROM DUAL test-while-idle: true test-on-borrow: true test-on-return: false filters: stat,wall,log4j2 slave: url: jdbc:mysql://127.0.0.1:3307/test?characterEncoding=UTF-8&autoReconnect=true&zeroDateTimeBehavior=convertToNull&useUnicode=true driver-class-name: com.mysql.jdbc.Driver username: test password: 123 initial-size: 5 max-active: 10 min-idle: 5 max-wait: 60000 time-between-eviction-runs-millis: 3000 min-evictable-idle-time-millis: 300000 validation-query: SELECT 'x' FROM DUAL test-while-idle: true test-on-borrow: true test-on-return: false filters: stat,wall,log4j2
2. 通过MybatisAutoConfiguration实现多数据源注入:
@Configuration
@EnableTransactionManagement
public class DataSourceConfiguration extends MybatisAutoConfiguration {
@Value("${druid.type}")
private Class dataSourceType;
@Bean(name = "masterDataSource")
@Primary
@ConfigurationProperties(prefix = "druid.master")
public DataSource masterDataSource(){
return DataSourceBuilder.create().type(dataSourceType).build();
}
@Bean(name = "slaveDataSource")
@ConfigurationProperties(prefix = "druid.slave")
public DataSource slaveDataSource(){
return DataSourceBuilder.create().type(dataSourceType).build();
}
@Bean
@Override
public SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {
return super.sqlSessionFactory(dataSource());
}
@Bean(name = "dataSource")
public AbstractRoutingDataSource dataSource() {
MasterSlaveRoutingDataSource proxy = new MasterSlaveRoutingDataSource();
Map targetDataResources = new HashMap<>();
targetDataResources.put(DbContextHolder.DbType.MASTER, masterDataSource());
targetDataResources.put(DbContextHolder.DbType.SLAVE, slaveDataSource());
proxy.setDefaultTargetDataSource(masterDataSource());
proxy.setTargetDataSources(targetDataResources);
proxy.afterPropertiesSet();
return proxy;
}
} 3. 基于 AbstractRoutingDataSource 和 AOP 的多数据源的配置
我们自己定义一个DataSource类，来继承 AbstractRoutingDataSource：
public class MasterSlaveRoutingDataSource extends AbstractRoutingDataSource {
@Override
protected Object determineCurrentLookupKey() {
return DbContextHolder.getDbType();
}
}这里通过determineCurrentLookupKey（）返回的不同key到sqlSessionFactory中获取对应数据源然后使用ThreadLocal来存放线程的变量，将不同的数据源标识记录在ThreadLocal中
public class DbContextHolder {
public enum DbType{
MASTER, SLAVE
}
private static final ThreadLocal contextHolder = new ThreadLocal<>();
public static void setDbType(DbType dbType){
if (dbType==null) {
throw new NullPointerException();
}
contextHolder.set(dbType);
}
public static DbType getDbType(){
return contextHolder.get()==null?DbType.MASTER:contextHolder.get();
}
public static void clearDbType(){
contextHolder.remove();
}
} 4. 注解实现
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface ReadOnlyConnection {
}@Aspect
@Component
public class ReadOnlyConnectionInterceptor implements Ordered {
@Around("@annotation(readOnlyConnection)")
public Object proceed(ProceedingJoinPoint proceedingJoinPoint, ReadOnlyConnection readOnlyConnection) throws Throwable {
try {
DbContextHolder.setDbType(DbContextHolder.DbType.SLAVE);
Object result = proceedingJoinPoint.proceed();
return result;
}finally {
DbContextHolder.clearDbType();
}
}
@Override
public int getOrder() {
return 0;
}
}5. 应用方式：
service层接口增加ReadOnlyConnection注解即可：
@ReadOnlyConnectionpublic CommonPagingVOpagingByCondition(GroupGoodsCondition condition, int pageNum, int pageSize) { Page page = PageHelper.startPage(pageNum, pageSize).doSelectPage(() -> groupGoodsMapper.listByCondition(condition)); return CommonPagingVO.get(page,page.getResult()); }
对于未加ReadOnlyConnection注解的默认使用masterDataSource。
到此，相信大家对“怎么用SpringBoot + Mybatis多数据源配置实现读写分离”有了更深的了解，不妨来实际操作一番吧！这里是创新互联网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！