create a file in java:

1)public void append( string text, string filename) : it has to append text to the text file file name and if any errors occur, do nothing

2)public void getLetter(string inputfile name, string outputfilename) : take first letter from each word in input file, translate them to uppercase, concatenate them together and place result in output file. if there is exception, catch it

3)public int count(string word, string filename) : count the number of times word appears in textfile name , if exception occurs , returns -1

4) public double sumbumber( string inputfilename) : input file name s the name of a binary file, first entry is type int , read all the doubles sum them and return results, if exception occurs return -1.0