Add factory methods for common exceptions with formatted messages

Original issue created by electrum on 2013-04-23 at 10:31 PM

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It’s common to be in a situation where precondition is known to be violated, but the condition can’t be checked for directly by a Precondition method. For example:

if (...) {
} else if (...) {
} else {
  // illegal argument
}

When this occurs, we want to throw an exception with a formatted message, so we have two options:

1. Use checkArgument() or checkState() with “false” as the condition
2. Throw the exception and use String.format()

The first option has the advantages of being shorter and providing safety in the case of a malformed format string. But it still looks a bit ugly and seems less than ideal.

It would be nice to have factories that take Precondition-like format strings for at least the following common exceptions:

• IllegalArgumentException
• IllegalStateException
• AssertionError
• RuntimeException
• UnsupportedOperationException

[dimo414]

Actual exception factory methods is still something being considered, but formatted messages are now possible as of 7fe1702a. CC @cpovirk.

[cpovirk]

(But there is also the general issue of whether such a small improvement justifies all the code-review comments about whether to use that API, even if some tools add review comments to suggest the API automatically.)