How to create multiple database connections for different databases in java
I have an application which uses four databases in different geographical locations. All the databases contains same tables and only the database name is different according to the location. I have to create some reports in my application which uses data from each database. What would be the proper way to create those database connection from a java application and is there a suitable design pattern for this task which I could use?
Answer
As you have not tagged your question with any of this, hibernate, JPA, ORM, I assume you are dealing with plain JDBC.
Having said that, I suggest you to have a DAO layer to deal with underlying databases, and leave the connection details to specific implementations. You can configure your connection strings in some .properties files, lets say.
[Complement]
You can also make use of DAO factory, an implementation of Abstract Factory or Factory Method pattern, whichever suits here.
[Links]
- A very fine implementation of DAO and DAO Factory, by BalusC
- Core J2EE Patterns -- arguably dated but might provide some idea.