I need help with a project that i'm working on called TextStatistics on java, I have no clue on how to do number 2 thru 5. above is the TextStatisticsInterface.java

2 Interface to get statistics from a text file. Used in the testing program. 3 author CS121 Instructors 5 public interface TextStatisticsInterface *greturn the number of characters in the text file public int getcharCount); kx *greturn the number of words in the text file public int getwordCount ); *greturn the number of lines in the text file public int getLineCountO: kok * greturn the letterCount array with locations [o].. [25] for 'a'through 'z' public intI] getLetterCount); * greturn the wordLengthCount array with locations [o]..[23] with location [i] * storing the number of words of length i in the text file. Location [o] is not used. * Location [23] holds the count of words of length 23 and higher. public intI] getwordLengthCount ); kok * greturn the average word length in the text file public double getAveragewordLength)