HANDLING EXCEPTIONS AND EVENTS - Java Programming: From Problem Analysis to Program Design - page 740

As we have seen in the previous chapters, as an input to a dialog box or a text field, Java
programs accept only strings as input. Numbers, integer or decimal, are entered as
strings. We then use the method parseInt of the class Integer to convert an
integer string into the equivalent integer. If the string containing the integer contains
only digits, the method parseInt will return the integer. However, if the string
contains a letter or any other nondigit character, the method parseInt throws a
NumberFormatException . Similarly, the method parseDouble also throws this
exception if the string does not contain a (valid) number. The programs that we've
written up to this point ignored these exceptions. Later in this chapter we show how to
handle these and other exceptions.
Tables 11-10, 11-11, and 11-12 list some of the exceptions thrown by the methods of the
class es Integer , Double , and String .

TABLE 11-10 Exceptions Thrown by the Methods of the class Integer

Method Exception Thrown Description

The string str
does not contain
an int value.

parseInt(String str) NumberFormatException

The string str
does not contain
an int value.

valueOf(String str) NumberFormatException

TABLE 11-11 Exceptions Thrown by the Methods of the class Double

Method Exception Thrown Description

The string
str does
not contain
a double
value.

parseDouble(String str) NumberFormatException

The string
str does
not contain
a double
value.

valueOf(String str) NumberFormatException