Task
Consider a system for processing names and addresses from a mailing list. A Recipients class will be used as part of this system. The lines in the mailing list are stored in an ArrayList, a private instance variable in the Recipients class. The blank line that separates recipients in the mailing list is stored as the empty string in this list, and the final element in the list is an empty string. A portion of the mailing list is shown below, with the corresponding part of the ArrayList.
Mr. J. Adams
6 Rose St.
Ithaca, NY 14850
Jack S. Smith
12 Posy Way
Suite 201
Glendale, CA 91203
Ms. M.K. Delgado
2 River Dr.
New York, NY 10013
The Recipients class that processes this data is shown below.
public class Recipients
{
/** The list of lines in the mailing list */
private List<String> lines;
/** Constructor. Fill lines with mailing list data.
* Postcondition:
* - Each element in lines is one line of the mailing list.
* - Lines appear in the list in the same order
* that they appear in the mailing list.
* - Blank line separators in the mailing list are stored
* as empty strings.
*/
public Recipients()
{ /* implementation not shown */ }
/** Postcondition: Returns the city contained in the cityZip
* string of an address.
* @param cityZip contains the city, state, and zipcode
* line of an address
* @return the city substring contained in cityZip
*/
public String extractCity(String cityZip)
{ /* to be implemented in part (a) */ }
/** Precondition: The recipient name is the first line of each
* label on the mailing list.
* Postcondition: Prints a list of recipient names to console,
* one per line.
*/
public void printNames()
{ /* to be implemented in part (b) */ }
/** Postcondition: Returns the address of the recipient with
* the specified name.
* @param name a name in the lines ArrayList
* @return the address of the recipient with the given name
*/
public String getAddress(String name)
{/* to be implemented in part (c) */}
//Other methods are not shown.
}
a) Write the extractCity method of the Recipients class. In the cityZip parameter the city is followed by a comma, then one blank space, then two capital letters for a state abbreviation, then a space and 5-digit zip code. For example, if cityZip is "Ithaca, NY 14850", the method call extractCity(cityZip) should return "Ithaca".
Information repeated from the beginning of the question
public class Recipients
private List<String> lines
public Recipients()
public String extractCity(String cityZip)
public void printNames()
public String getAddress(String name)
Complete method extractCity below.
/** Postcondition: Returns the city contained in the cityZip
* string of an address.
* @param cityZip contains the city, state, and zipcode
* line of an address
* @return the city substring contained in cityZip
*/
public String extractCity(String cityZip)
b) Write the printNames method of the Recipients class. Method printNames prints the names of all recipients to the console, one per line. For the sample part of the mailing list shown at the beginning of the question, the output for printNames would be:
Mr. J. Adams
Jack S. Smith
Ms. M.K. Delgado
Complete method printNames below.
/** Precondition: The recipient name is the first line of each
* label on the mailing list.
* Postcondition: Prints a list of recipient names to console,
* one per line.
*/
public void printNames()
c) Write the getAddress method of the Recipients class. This method should return a string that contains only the address of the corresponding name parameter. For example, if name is "Jack S. Smith", a string containing the three subsequent lines of his address should be returned. This string should contain line breaks in appropriate places, including after the last line of the address. This ensures that the address will have the proper address format when printed by a client class.
Complete method getAddress below.
/** Postcondition: Returns the address of the recipient with
* the specified name.
* @param name a name in the lines ArrayList
* @return the address of the recipient with the given name
*/
public String getAddress(String name)