How to properly clean up JDBC resources in Java?

Question

What is considered best practices when cleaning up JDBC resources and why? I kept the example short, thus just the cleaning up of the ResultSet.

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Answer 1

Nowadays JDK 7 gives you the easiest option to clean up resources:

String query = "select COF_NAME, PRICE from COFFEES";
try (Statement stmt = con.createStatement()) {
    ResultSet rs = stmt.executeQuery(query);
    while (rs.next()) {
        String coffeeName = rs.getString("COF_NAME");
        float price = rs.getFloat("PRICE");
        System.out.println(coffeeName + ", "  + price);
    }
}

The try statement ensures that each resource is closed at the end of the statement. See http://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html