apollo-common/src/main/java/com/ctrip/framework/apollo/common/datasource/TitanEntityManager.java/TitanEntityManager/datasource
class TitanEntityManager:  @SuppressWarnings({"rawtypes", "unchecked"})
  @Bean
  public DataSource datasource() throws Exception {
    Class clazz = Class.forName("com.ctrip.datasource.configure.DalDataSourceFactory");
    Object obj = clazz.newInstance();
    Method method = clazz.getMethod("createDataSource", new Class[] {String.class, String.class});
    DataSource ds = ((DataSource) method.invoke(obj,
        new Object[] {settings.getTitanDbname(), settings.getTitanUrl()}));
    Tracer.logEvent("Apollo.Datasource.Titan", settings.getTitanDbname());
    return ds;
  }