Question

I am going through a Spring book to learn Spring. Having gone through sections about the JDBCTemplate i was surprised to find that Spring handles most of the SQLException exceptions differently.

For example, all checked exceptions are converted to unchecked exceptions. What exactly is the benefit of this?

In my experience, the majority of SQL exceptions should be handled. For example, we have an application that talks to an Oracle PL/SQL procedure. The call to the PL/SQL procedure can return an ORA-01403: no data found exception. This kind of exception is one that you usually recover from by displaying an error message to the user. e.g. A search result did not return anything.

How would this kind of a checked exception be handled in Spring if all exceptions are unchecked i.e. Spring wont force you to handle them?

I know that you can catch RuntimeExceptions but i quite liked the idea that you are forced to handle checked exceptions. What benefit does converting some of the checked exceptions to unchecked exceptions provide?

Answer 1

Some people don’t like checked exceptions, as they force you to do some exception management. I guess the Spring guys are of this kind.

Personally I prefer to do things as they were intended to be made:

try {
    // execute some SQL
} catch (SQLException ex) {
    if (ex is an expected condition) {
        // deal with it: for example with a "no data found" condition
        // this might mean returning null, or throwing some kind of business exception, such as
        // NoEmployeeFoundException, or whatever
    } else {
        // this is a programming / environment error
        // throw as unchecked exception
        throw new RuntimeException(ex);
    }
}

Of course the downside of this approach is that is more work. The upside is that you have explicitly stated in code which are the “expected” circumstances and which ones should not happen ever.