How to create two connections with different databases?

You can open two connections to different databases and then insert the data read from one database into the other more or less like this:

String urlMySql = "jdbc:mysql://localhost:3306/seu_database_mysql";
String urlDb2 = "jdbc:db2://localhost:50000/seu_database_db2";

Connection connMySql = DriverManager.getConnection(urlMySql);
Connection connDb2 = DriverManager.getConnection(urlDb2);

PreparedStatement selectDb2 = connDb2.prepareStatement("SELECT * FROM TABELA");
ResultSet rsDb2 = selectDb2.executeQuery();

while (rsDb2.next()) {
    PreparedStatement insertMySql = connMySql.prepareStatement("INSERT INTO OUTRA_TABELA VALUES...");
    insertMySql.setXXX(rsDb2.getXXX(...));
    insertMySql.executeUpdate();
}

It is also valid to encapsulate% s of% s in DAOs, put connections into pools, or separate any database operation into multiple classes and / or various methods. Just keep in mind that there may be more than one connection to the active database at the same time (along with their Connection s and PreparedStatement s).

You can not have a single con referencing two database connections. You definitely need to keep two different references.

Connection con1 = DriverManger.getConnection( connect1 );  
Connection con2 = DriverManger.getConnection( connect2 );  

There is no other alternative.

Solution 1: Create multiple methods to return local and remote connection.

public Connection getLocalConnection() {
  ...
  Connection localCon = DriverManger.getConnection( connect1 );  
  ...
  return localCon;
}

public Connection getRemoteConnection() {
  ...
  Connection remoteCon = DriverManger.getConnection( connect2 );  
  ...
  return remoteCon;
}

Solution 2: If you want to generate so much connection on each call and return them, you'd better use an object from the list to go back:

public List<Connection> createConnection() {
  ...
  Connection localCon = DriverManger.getConnection( connect1 );  
  Connection remoteCon = DriverManger.getConnection( connect2 );  
  ...
  List<Connection> connectionsList = new ArrayList<Connection>( 2 );
  connectionsList.add( localCon );
  connectionsList.add( remoteCon );
  ...
  return connectionsList;
}

I'd rather use Solution 1, because sometimes you might be checking some data in a single database.