使用过springboot的人都知道想要配置多数据源很麻烦，需要自己写Datasource、SqlsessionFactory、MapperScannerConfigurer三个bean的注入，并且不能动态配置，对于开发人员要求高。
国信zebra架构实现了动态多数据源配置，实现思路是在spring bean初始化前，读取配置文件的datasource配置，然后根据配置文件信息，动态将Datasource、SqlsessionFactory、MapperScannerConfigurer三个bean注入到spring容器中。
第一步：设计配置文件内容
#SQL日志输出配置
logging.level.com.guosen.zebra.hello.mapper=debug
#第一个数据源的数据库url
zebra.database.url[0]=jdbc:jtds:sqlserver://0.0.0.0:1433/tst
#第一个数据源的数据库用户名
zebra.database.username[0]=sa
#第一个数据源的数据库密码
zebra.database.pwd[0]=12345678
#第一个数据源的mapper包名
zebra.database.basePackage[0]=com.guosen.zebra.hello.mapper
#第一个数据源的名称
zebra.database.dataSourceName[0]=gum
第二步：设计初始化bean的类
public class DruidDBConfig {
private DruidDbProperties druidDbProperties;
//初始化DataSource
public BeanDefinitionBuilder createDataSource(String url, String username, String password) {
BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder .genericBeanDefinition(DruidDataSource.class); beanDefinitionBuilder.addPropertyValue("url", url);
beanDefinitionBuilder.addPropertyValue("username", username);
beanDefinitionBuilder.addPropertyValue("password", password);
beanDefinitionBuilder.addPropertyValue("initialSize", getDruidDbProperties().getInitialSize()); beanDefinitionBuilder.addPropertyValue("minIdle", getDruidDbProperties().getMinIdle()); beanDefinitionBuilder.addPropertyValue("maxActive", getDruidDbProperties().getMaxActive()); beanDefinitionBuilder.addPropertyValue("maxWait", getDruidDbProperties().getMaxWait()); beanDefinitionBuilder.addPropertyValue("timeBetweenEvictionRunsMillis", getDruidDbProperties().getTimeBetweenEvictionRunsMillis());
beanDefinitionBuilder.addPropertyValue("minEvictableIdleTimeMillis", getDruidDbProperties().getMinEvictableIdleTimeMillis()); beanDefinitionBuilder.addPropertyValue("validationQuery", getDruidDbProperties().getValidationQuery()); beanDefinitionBuilder.addPropertyValue("testWhileIdle", getDruidDbProperties().isTestWhileIdle()); beanDefinitionBuilder.addPropertyValue("testOnBorrow", getDruidDbProperties().isTestOnBorrow()); beanDefinitionBuilder.addPropertyValue("testOnReturn", getDruidDbProperties().isTestOnReturn());
return beanDefinitionBuilder;
}
//初始化SqlSessionFactory
public BeanDefinitionBuilder createSqlSessionFactory(DataSource dataSource) throws Exception {
BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder .genericBeanDefinition(SqlSessionFactoryBean.class); beanDefinitionBuilder.addPropertyValue("dataSource",dataSource);
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
Resource[] rs = resolver.getResources("classpath:*Mapper.xml");
System.err.println("get Mapper Resources size" +rs.length);
beanDefinitionBuilder.addPropertyValue("mapperLocations", rs);
return beanDefinitionBuilder;
. }
//初始化 MapperScannerConfigurer
public BeanDefinitionBuilder createMapperScannerConfigurer(String sqlSessionFactoryName, String basePackage) throws Exception { BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder .genericBeanDefinition(MapperScannerConfigurer.class); beanDefinitionBuilder.addPropertyValue("sqlSessionFactoryBeanName", sqlSessionFactoryName); beanDefinitionBuilder.addPropertyValue("basePackage", basePackage);
return beanDefinitionBuilder;
}
//初始化 DataSourceTransactionManager
public BeanDefinitionBuilder createAnnotationDrivenTransactionManager(DataSource dataSource) {
BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder .genericBeanDefinition(DataSourceTransactionManager.class); beanDefinitionBuilder.addConstructorArgValue(dataSource);
return beanDefinitionBuilder;
}
public static DruidDBConfig create() throws IOException {
DruidDbProperties properties = new DruidDbProperties();
DruidDBConfig conf = new DruidDBConfig();
conf.setDruidDbProperties(properties);
return conf;
}
}
第三步：将初始化的bean定义注入到spring容器中
@Configuration
@EnableConfigurationProperties(DatabasesProperties.class)
public class DatabaseInit implements BeanDefinitionRegistryPostProcessor, ApplicationContextAware {
private static ApplicationContext ctx;
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
ctx = applicationContext;
}
@Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
int idx = 0;
try {
for (String url : databasesProperties.getUrl()) {
// 注入datasource
BeanDefinitionBuilder ds = druidDBConfig.createDataSource(url, databasesProperties.getUsername().get(idx), databasesProperties.getPwd().get(idx)); registry.registerBeanDefinition(databasesProperties.getDataSourceName().get(idx), ds.getBeanDefinition());
// 注入sessionFactory
DataSource dataSource = (DataSource) ctx.getBean(databasesProperties.getDataSourceName().get(idx)); BeanDefinitionBuilder sqlSessionFactory = druidDBConfig.createSqlSessionFactory(dataSource); registry.registerBeanDefinition("SqlSessionFactory" + databasesProperties.getDataSourceName().get(idx), sqlSessionFactory.getBeanDefinition());
// 注入mapperscan
BeanDefinitionBuilder sacnner = druidDBConfig.createMapperScannerConfigurer( "SqlSessionFactory" + databasesProperties.getDataSourceName().get(idx), databasesProperties.getBasePackage().get(idx)); registry.registerBeanDefinition( "MapperScannerConfigurer" + databasesProperties.getDataSourceName().get(idx), sacnner.getBeanDefinition());
// 注入TX
BeanDefinitionBuilder tm = druidDBConfig.createAnnotationDrivenTransactionManager(dataSource); r registry.registerBeanDefinition("TransactionManager" + databasesProperties.getDataSourceName().get(idx), tm.getBeanDefinition());
idx++;
}
}
}
}
测试
public class HelloServiceImpl implements HelloService{
@Autowired
ConfMapper mapper;
public HelloReply sayHello(HelloRequest hellorequest) {
List> list= mapper.getServerVersionConf(null);
System.out.println(list);
HelloReply reply = new HelloReply();
reply.setMessage(test.sayHello(hellorequest.getName()));
System.out.println("from method");
return reply;
}
测试结果
2018-01-25 10:26:44.506 DEBUG 17800 --- [ault-executor-0] c.g.z.h.m.C.getServerVersionConf : ==> Preparing: SELECT * FROM SERVER_VERSION_CONF
2018-01-25 10:26:44.693 DEBUG 17800 --- [ault-executor-0] c.g.z.h.m.C.getServerVersionConf : ==> Parameters:
2018-01-25 10:26:44.835 DEBUG 17800 --- [ault-executor-0] c.g.z.h.m.C.getServerVersionConf : <== Total: 4
搞定！
