SpringBoot中数据源读写分离配置

       开发中常用到主从数据库来提高系统的性能。怎么样才能方便的实现主从读写分离呢？ 通过事务注解里面的可读属性readOnly的取值来自动切换数据源, 从而实现数据库读写分离。

1.主备数据源配置

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@Configuration @PropertySources ({ @PropertySource ( "classpath:travel.properties" )}) @EnableTransactionManagement @MapperScan (basePackages =  "com.ethen.travel" , annotationClass = Mapper. class , sqlSessionFactoryRef =  "sqlSessionFactory" ) public class DataSourceConfig { @Autowired private Environment props; private BasicDataSource abstractDataSource() { BasicDataSource abstractDataSource =  new BasicDataSource(); abstractDataSource.setDriverClassName(props.getProperty( "db.driverClassName" )); abstractDataSource.setUsername(props.getProperty( "db.username" )); abstractDataSource.setPassword(props.getProperty( "db.password" )); abstractDataSource.setTestOnBorrow( true ); abstractDataSource.setTestWhileIdle( true ); abstractDataSource.setValidationQuery( "SELECT 1" ); abstractDataSource.setTimeBetweenEvictionRunsMillis( 300000 ); abstractDataSource.setNumTestsPerEvictionRun( 10 ); abstractDataSource.setMinEvictableIdleTimeMillis(- 1 ); abstractDataSource.setPoolPreparedStatements( true ); abstractDataSource.setMaxOpenPreparedStatements( 100 ); return abstractDataSource; } @Bean (destroyMethod =  "close" , name= "master" ) @Primary public BasicDataSource masterDataSource() { BasicDataSource masterDataSource = abstractDataSource(); masterDataSource.setUrl(props.getProperty( "db.master.url" )); masterDataSource.setMaxTotal(Integer.parseInt(props.getProperty( "db.master.maxActive" ))); masterDataSource.setMaxIdle(Integer.parseInt(props.getProperty( "db.master.maxIdle" ))); masterDataSource.setMinIdle(Integer.parseInt(props.getProperty( "db.master.maxIdle" ))); return masterDataSource; } @Bean (destroyMethod =  "close" , name= "slave" ) public BasicDataSource slaveDataSource() { BasicDataSource masterDataSource = abstractDataSource(); masterDataSource.setUrl(props.getProperty( "db.slave.url" )); masterDataSource.setMaxTotal(Integer.parseInt(props.getProperty( "db.slave.maxActive" ))); masterDataSource.setMaxIdle(Integer.parseInt(props.getProperty( "db.slave.maxIdle" ))); masterDataSource.setMinIdle(Integer.parseInt(props.getProperty( "db.slave.maxIdle" ))); return masterDataSource; } @Bean (name= "dynamicDataSource" ) public ReplicationRoutingDataSource dynamicDataSource()  throws IOException { Map<Object, Object> targetDataSources =  new HashMap<>(); targetDataSources.put( "master" , masterDataSource()); targetDataSources.put( "slave" , slaveDataSource()); ReplicationRoutingDataSource dynamicDataSource =  new ReplicationRoutingDataSource(); dynamicDataSource.setDefaultTargetDataSource(targetDataSources.get( "master" )); dynamicDataSource.setTargetDataSources(targetDataSources); return dynamicDataSource; } public DataSource dataSource()  throws IOException { return new LazyConnectionDataSourceProxy(dynamicDataSource()); } @Bean public SqlSessionFactory sqlSessionFactory()  throws Exception { SqlSessionFactoryBean sqlFactory =  new SqlSessionFactoryBean(); sqlFactory.setDataSource(dataSource()); sqlFactory.setConfigLocation( new ClassPathResource( "mybatis-config.xml" )); sqlFactory.setTypeAliasesPackage( "com.ethen.travel" ); return sqlFactory.getObject(); } @Bean public DataSourceTransactionManager txManager()  throws IOException { DataSourceTransactionManager dataSourceTXManager =  new DataSourceTransactionManager(); dataSourceTXManager.setDataSource(dataSource()); AnnotationTransactionAspect.aspectOf().setTransactionManager(dataSourceTXManager); return dataSourceTXManager; } }

2.数据源动态切换

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@Slf4j public class ReplicationRoutingDataSource  extends AbstractRoutingDataSource { private static final String SLAVE_LOOKUP_KEY =  "slave" ; private static final String MASTER_LOOKUP_KEY =  "master" ; @Override protected Object determineCurrentLookupKey() { String lookupKey = TransactionSynchronizationManager.isCurrentTransactionReadOnly() ? SLAVE_LOOKUP_KEY : MASTER_LOOKUP_KEY; log.debug( "connected DataSource :{}" , lookupKey); return lookupKey; } }

    上面只贴出了关键代码，数据库的配置文件就没有贴出来了。这样就可以很方便的实现的主从数据源动态切换，实现读写分离。