Purpose:

The purpose of this exercise is to have you create some Exception classes, then throw these exceptions when appropriate and provide a catch handler to catch the thrown exceptions.

 

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Demonstration:

The demonstration program tries to collect input from the user to create a Person, an Address and a PhoneNumber object based on the information collected. The program is to use exception handling to screen out invalid input and continues to re-prompt the user until they provide valid input. Examine the Main.java class and see where the prompting and exception throwing is being done. Currently the code throws an IllegalNameSpellingException exception. It also throws a general Exception is there are not enough tokens in an address input to possibly be a valid address with postal code. The screen capture below shows the behaviour of the demo code. Notice that there are still several errors in the information collected including: a last name  not capitalized, the word "street not capitalized, and an incorrectly formatted phone number. We will fix this problems with exception handling.

The Person class demonstrates the structure of a class that throws exceptions, and the main program shows how to catch those exceptions. The Person class's constructor currently will throw an IllegalNameSpellingException if the names contain characters that are not letters. Also the Address class currently throws a general Exception if there are just too few tokens in the input string to be an address and postal code. Examine the code to see how is done and how the exceptions are caught.
 

Your task is to add new Exception classes and modify the Person, the Address and PhoneNumber classes so that the specific requirements below are satisfied. The main program has catch blocks to catch a general Exception object. You should replace these in the code with catch blocks that can catch the new types of exceptions that you create.

To complete this tutorial you will have to examine parts of the input strings collected from the user. The are many ways you can do this. You can use a for-loop to examine individual characters and look for separators like blanks. Alternatively you can use one of the String methods, like split(),  that can break a string up into individual words or tokens.

Here are some useful String methods that might be helpful

aString.charAt(i);  //returns the char at position i, counting from 0,  in the string aString
aString.substring(i,n); //returns a String that is the substring of characters in aString from position i to n-1
aString.trim(); //returns a substring that is aString with leading and trailing blanks removed
aString.split(" "); returns an String[] of the substrings of aString delimited by blanks

For example, the following code

System.out.println("==============");
String test = "The 11 little foxes";
String[] sa = test.split(" ");
for(int i=0; i<sa.length; i++)
System.out.println(sa[i]);

 will produce the following output:

==============
The
11
little
foxes

There are many other useful string methods. You should look at the Java API documentation for others you might find useful.

There are also useful Character methods that you can use to determine whether a character is a digit or a letter. Here are some useful expressions:

Character.isLetter( c ); //returns true if char c is a letter and false otherwise

Character.isDigit( c ); //returns true if char c is a digit and false otherwise

There are many other useful Character methods. You should look at the Java API documentation for others you might find useful.

 

 

Specific Requirements and Suggestions
 

Person Requirements
 

1) Person's names must not contain characters other than letters, otherwise you should throw a IllegalNameSpellingException.
 

2) A Person's names must start with a capital letter, otherwise you should throw a ProperNameNotCapitalizedException.
 

Address Requirements
 

1) Addresses must have at least a non-empty string and a valid postal code, otherwise you should throw a IncompleteAddressException.
 

2) The names of streets, cities, (i.e. any words in the address) must start with capital letters otherwise you should throw an ProperNameNotCapitalizedException.
 

3) The postal code should be of the form " letter digit letter space digit letter digit" otherwise you should throw an InvalidPostalCodeFormatException
 

4) The letters in the postal code should all be capital letters otherwise you should throw an InvalidPostalCodeFormatException
 

Phone Number Requirements)
 

Phone numbers can be 7 digits or 10 digits.

1) A 7 digit number must have a dash between the 3rd and 4th digit. (e.g. 234-1233) otherwise you should throw an InvalidLocalPhoneNumberException. (Note there should not be blanks before or after the dash).
 

2) A 10 digit number must have the area code in brackets, a space between the area code and local 7-digits and a dash between the 3rd and 4th digit of the 7 digit portion. (e.g. (613)234-1233) otherwise you should throw an InvalidPhoneNumberException. Note there should not be any blanks within the phone number.
 

To complete this tutorial it must not be possible for the TA to enter data, and have that data accepted, if it violates any of the above requirements.
 

 

When you have completed the code demonstrate to the tutorial TA that you have satisfied all  the requirements. (You need to demonstrate your tutorials results to the TA to get credit for the tutorial. )