How to retry Oracle db connection with different server?

[Ben Hen]

I have 2 servers - a primary and a backup. When the first connection fails, how can I get it to try the second server?
dbServer1 = "server1";
dbServer2 = "server2";

My connection:

Connection conn = null;
try
{
	Class.forName("oracle.jdbc.driver.OracleDriver");
	conn = DriverManager.getConnection(dbServer1, dbUser, dbPass);
	Statement stmt = conn.createStatement();

	////////////////////////////
	////////SELECT from HR TABLE where WinLogin = s
	String sqlSelect = "";
//etc...

}

I've tried if (conn == null) but it doesn't work.

Thanks!

[Stefan Evans]

Well there are a couple of scenarios
1 - Connection cannot be established and it throws a SQLException. You need to catch that exception, and then "handle" it by trying the fallback server.


2 - Connection succeeds. Taking a look at the API for java.sql.Connection maybe as well as the test for null, you could try connection.isValid() ?

This sort of logic might be better encapsulated in a java class, or even a JDBC DataSource.
The standard approach in most java apps these days is to use a JNDI Datasource to get connections from rather than the DriverManager.