Search an ArrayList for a particular Object

Question

I have a class called Person. It has the following attributes; It has 2 attributes, ID, and Telephone. 1 person can have many

Answer 1

//...
Person foundPerson = null;
for (Person p : personList){
    if (p.getTelephone() == telephone){
         foundPerson = p; //or simply return it from there
         break;
    }
}

For implementing hashCode and equals you can observe this tutorial.