WhiningBuilder
From APIDesign
One problem with ChameleonBuilder is that the change of the return type works only for a single essential attribute. Can we modify the [[builder] pattern to work with multiple such attributes? Another problem is the reported error - it doesn't push the user towards proper fix. Can we improve that and encourage cluelessness in users of our builders?
Multiple Throws
Java allows only a single return value - yet, it allows multiple throws - and throwing an exception is kind a return value as well. As the BuilderWithConditionalException it is possible use a generic type parameter to control whether the exception thrown from the build() method is checked exception or unchecked one. Let's do the same with multiple throws for two essential attributes (name and mimeType):
public final class Builder<MissingName extends Exception,MissingMIMEType extends Exception> { } [[TBD]]