In Java please and can you explain the question.

(120 pts) Write a C++ or Java class that stores a data set of strings consisting only of numbers ('0'-'9') and English letters (both lower and upper cases). Your class needs to implement the following dictionary functions. Make sure also that your program contains reasonable error checking. Two constructor methods/functions, o one that does not have any parameter and initializes the data set as empty set, and o one that takes a parameter consisting of a set of strings and initialize the data set with those strings. int search(strings) This function returns the number of copies of strings in the data set, or if the data set does not contain the string s. void add(string s) This function adds a copy of the strings to the data set. void remove(string s) This function removes a copy of the strings from the data set or does nothing if the data set does not contain the string s. void print() This function prints all strings in the data set (in no particular order). In case there are identical string in the data set all copies of the string contained in the data set will be printed