JAVA

I am currently trying to compile my ContactList class and I cannot figure out the Symbol not found error. What i am trying to do is implement an array list using the contact class that i created. So basically an arrayList of contacts. I am working on the toString method but the error i am getting is the symbol not found and i cant figure out whats wrong.

Line 14: Col 2 3 sh -c javac -classpath .:target/dependency/* d. \$(find . -type f-name ' .java') ./HW/HW1/ContactList. java:22: error: cannot find symbol str. append( currentContact.getFirstName() + " " + currentContact.getLastName() + " "); symbol: method getFirstName() location: variable currentContact of type Contact where Contact is a type-variable: contacts = new ArrayList (10); Contact extends object declared in class ContactList Note: ./HW/HW1/Main. java uses unchecked or unsafe operations