I have to write tests with String Test framework where many DB connections was used.
In test I don't need all data sources but Spring want them all to inject.
Are there any standard or well known fake javax.sql.DataSource implementation just to satisfy Spring DI mechanic?
You can use Mockito framework. Using Springockito you can mock your datasources on a Spring environment.
Credit of this resource is for kubek2k in this SO answer.