Checked and Unchecked exceptions

[Josh Rema]

Checked and Unchecked exceptions how can you tell the difference.

[wise owen]

Checked exceptions are all exception classes instantiated from the Exception class, or from subclasses of Exception other than RuntimeException and its subclasses.

For checked exceptions, the code in your method must do something for them and you cannot be ignored them when you write your code. The compiler checks each method to be sure that it does.
[ May 05, 2006: Message edited by: wise owen ]

[Josh Rema]

I understand that, but how can you tell with out memorizing all the exceptions that are subclassed under checked exceptions.

[wise owen]

That is a very good question. I agree with you that you can not tell without memorizing all the exceptions that are subclassed under checked exceptions.
[ May 05, 2006: Message edited by: wise owen ]

[marc weber]

My approach was to just memorize common unchecked exceptions, like:

ArithmeticException

ClassCastException

ConcurrentModificationException

IllegalArgumentException

IllegalMonitorStateException

IndexOutOfBoundsException

NullPointerException

NumberFormatException

[vignesh hariharan]

java API's naming convention is designed such that you can easily understand the way the exception is going to behave from its name itself.eg:ArrayIndexOutOfBound is this exception not clear from the name itself??? once you understand the exception type and its working you can easily have in mind. other than that i dont think you are explicitly needed to memorise them until it is very hard to understand. and mind that memorizing will not last for longer time... rather understand..

[marc weber]

Originally posted by vignesh hariharan:
java API's naming convention is designed such that you can easily understand the way the exception is going to behave from its name itself...

I would be careful, because that approach can be misleading. For example, the following could easily be seen as RuntimeExceptions, although they are actually checked Exceptions:

ClassNotFoundException

InterruptedException

IOException (including MalformedURLException)

etc.

[Josh Rema]

Thank you guys for all the advice. I believe I will look at the most common checked and unchecked exceptions and try to memorize; as well as, have a good understanding as to why they are being thrown. thx again

[K Vidhyakar]

hi friends,
in the exam it will be mentioned that its a checked or runtime Excepton. i got a question related exception and it was stated that
Note : all the methods in the IO package throws checked exception , including close();

so u dont need to memorize for the exam.
For real time projects, u just complie it. if it says it should be declared, then its a checked. !!!

Vidhyakar K

[Sasikanth Malladi]

Grr!!
I can't believe you said that. If you let the compiler decide how you write your programs you have a lot of learning to do!!!
Sashi