Data Structures and Algorithms in Java[1].pdf - Fulvio Frisone

goShopping(); // I don't have to try or catch
the exceptions
because
these along.
// which goShopping() might throw
// getReadyForClass() will just pass
}
makeCookiesForTA();
A function can declare that it throws as many exceptions as it likes. Such a listing
can be simplified somewhat if all exceptions that can be thrown are subclasses of
the same exception. In this case, we only have to declare that a method throws the
appropriate superclass.
Kinds of Throwables
Java defines classes Exception and Error as subclasses of Throwable,
which denotes any object that can be thrown and caught. Also, it defines class
RuntimeException as a subclass of Exception. The Error class is used
for abnormal conditions occurring in the run-time environment, such as running
out of memory. Errors can be caught, but they probably should not be, because
they usually signal problems that cannot be handled gracefully. An error message
or a sudden program termination is about as much grace as we can expect. The
Exception class is the root of the exception hierarchy. Specialized exceptions
(for example, BoundaryViolationException) should be defined by
subclassing from either Exception or RuntimeException. Note that
exceptions that are not subclasses of RuntimeException must be
declared in the throws clause of any method that can throw them.
2.3.2 Catching Exceptions
When an exception is thrown, it must be caught or the program will terminate. In
any particular method, an exception in that method can be passed through to the
calling method or it can be caught in that method. When an exception is caught, it
can be analyzed and dealt with. The general methodology for dealing with
exceptions is to "try" to execute some fragment of code that might throw an
exception. If it does throw an exception, then that exception is caught by having the
flow of control jump to a predefined catch block that contains the code dealing
with the exception.
The general syntax for a try-catch block in Java is as follows:
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