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Message:

Throwing exceptions from constructors

Posted by Mark E. on May 31, 2001 at 11:23 AM

My technical lead claims that throwing an exception from a constructor in Java may leave allocated memory that is not cleaned up and that we should do very little in a constructor and avoid throwing exceptions. I believe this to be wrong but could not find any definition of what happens to the allocated memory when the initialization of a class is interrupted by throwing an exception. Anyone know what the answer is? I prefer not having a two step process to initialize an object because then I have to put in initialization check in all the functions. Also, what is the value of a reference variable when initialzation is interupted? Does Java set it to null or just leave it what it was before? If it is the second, then I suppose that the reference could still be pointing to a valid object; assuming it was pointing to one before the attempt to initialize the new object:
MyClass objRef = new MyClass(goodArgument); // no exception
objRef = new MyClass(badArgument); // throws exception, what is objRef set to???