it requires two different classes : AddressBook and AddressBookEntry
You have provided code that shows the defination of AddressBook,
but where is AddressBookEntry ?
thats what the java compiler is saying:
"cannot find symbol class AddressBookEntry"
let me rephrase/interpret that:
"Dude, I want to run your program, but I am unable to find a class named 'AddressBookEntry'. Its probably in a file called AddressBookEntry.java,
have you forgotten to define such class? if you have defined it, is it in the same class path so that I may access it ?"