Is is common knowledge that people are quite often incompetent, and will provide wonderful software with the incorrect input. For example, if a program expects to find a list of integers on its command line, they will regularly give words like "cat" instead.

Write a program that expects to find a list of integers on its command line, and is robust against incorrect user input. Each correct integer found must be wrapped in an Integer object, and a ArrayList must be used to store the objects. After all the (correct integer) command line arguments have been stored in the ArrayList, the contents of the ArrayList must be output.

The program must:

• Loop through the command line Strings in the main method.
• For each command line String, call a separate "converter" method to try build an Integer object from the string.
• The converter method must try to convert its string argument (sent by the main) to a primitive integer. If that fails a NumberFormatException is thrown up to the main. Otherwise the primitive integer is printed out, and an Integer object created from the primitive integer is returned from the method up to the main method.
• The call from the main to the converter method must be within a try-catch block. If the object is built successfully it is added to the ArrayList (done in the main method). If a NumberFormatException exception is thrown by the method, an appropriate error message is output from within the catch block.

Converter method says integer OK - 12
Converter method says integer OK - 23
Catch block says the argument "cat" is ignored because cat
Converter method says integer OK - 34
Converter method says integer OK - 45
Catch block says the argument "dog" is ignored because dog
Converter method says integer OK - 56
Converter method says integer OK - 67

The ArrayList contents are:
Item 0 is 12
Item 1 is 23
Item 2 is 34
Item 3 is 45
Item 4 is 56
Item 5 is 67

You must ...

• Implement the program in Java (2.0%)

Answer

• ExceptionalIntegers.java