CODEWITHSUNDEEP
javaexception
jdoe
jdoe

Reputation: 57

Java: Throwing exception inside the catch block

Lets say I have a method combine

T[] combine(T[] arr1, T[] arr2, Comparator<T> cmp, Class<?> type) throws IllegalArgumentException{

...

}

And inside that I want to create an array using reflection. T[] newArray = (T[]) Array.newInstance(type, arr1.length+arr2.length);. If an error accors during initializing newArray I want to throw new IllegalArgumentExeption().

How should I do this preferably? Can I do this with try and catch blocks? Inside the try block I would try to initialize the array and inside the catch I would throw the IllegalArgumentEception.

Upvotes: 0

Views: 71

Answers (1)

davidxxx
davidxxx

Reputation: 131326

You could do as you suppose but I would be careful about two points :

  • catching any exception and not a specific exception

  • throwing the IllegalArgumentException by wrapping the caught exception. Having the full stracktrace may help to debug

For example :

try{
...
}
catch (Exception e){
    throw new IllegalArgumentException("exception during combine() invocation with params..." , e);
}

Note that declaring throws IllegalArgumentException in the method declaration is really not required as the client doesn't have any constraint to handle it : it is a RuntimeException.
It is like declaring throws NullPointerException for a method that can throw it.
If you want to constraint clients to handle the exception, use rather a checked Exception.

Upvotes: 2

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