please help JAVA

public class CodeConverter {

Map codeMap; // map from alphanumeric to Morse code

Map invCodeMap; // map from Morse code to alphanumeric

/** DO NOT MODIFY THE DECLARATION LINES ABOVE */

/** * Default constructor. Initialize the instance variable. */ public CodeConverter() { throw new UnsupportedOperationException("replace with your implementation"); }

/** * Read codeFile and beef up the code list. Each line in the codeFile has two * fields (letter, codeString) separated by a comma. * * @param codeFile * @throws IOException */ public void buildCodeTable(String codeFile) throws IOException { Scanner input = new Scanner(new File(codeFile));

// ADD YOU CODE HERE input.close(); }

/** * Convert a text to the corresponding Morse code sequence, and return the Morse * code sequence. Before conversion, convert all characters in the input text to * upper-cases and also remove all leading and trailing whitespace chars of the * input text. * * For each letter (A-Z) or a number in the text, the corresponding Morse code * will be added to the output code sequence. Between the Morse codes for * alphanumeric char, insert a space. The space in the text will be replaced * with three spaces. Ignore all other characters. * * For example, Both "A b" and "A% b" will be encoded to ".- -...". * * @param text * a sequence of characters. * @return the Morse code corresponding to the input text */ public String toMorseCode(String text) { throw new UnsupportedOperationException("replace with your implementation"); }

/** * Convert a Morse code sequence to the corresponding alphanumeric text, and * return the text. Before conversion, remove all leading and trailing * whitespace chars of the input text. * * Note that symbols are separated with a space. The three consecutive spaces * will be converted to a single space character in the output text. You may * want to maintain two maps for this assignment -- one for Text to Morse, and * the other for Morse to Text). * * For example, "... --- ..." will be converted to "SOS". * * @param morseCodeSeq * a sequence of Morse code symbols. * @return the text corresponding to the Morse code */ public String toAlphaNumeric(String morseCodeSeq) { throw new UnsupportedOperationException("replace with your implementation"); }

/** * This methods count how many Morse codes has symbols equal to the len input * parameter. For example, if the input parameter is 1, this method should * return 2 (The Morse code for 'E' is '.' and for 'T' is '-'.) * * @param len * @return the number of keys of which Morse code is encoded with 'len' symbols. */ public int countByCodeLength(int len) { throw new UnsupportedOperationException("replace with your implementation"); }

/** * The main method is not needed for this assignment but you can use it as a * driver to run a few test cases. It is recommended to write your tests in the * StudentTests class and run it as JUnit tests as you run PublicTests. * * @param args * @throws IOException */ public static void main(String[] args) throws IOException { CodeConverter codeConv = new CodeConverter(); codeConv.buildCodeTable("MorseCode.txt");

String morseCode = codeConv.toMorseCode("CMSC 131"); System.out.println(morseCode); String text = codeConv.toAlphaNumeric(morseCode); System.out.println(text); } }

the file MorseCode.txt contains the following

A,.- B,-... C,-.-. D,-.. E,. F,..-. G,--. H,.... I,.. J,.--- K,-.- L,.-.. M,-- N,-. O,--- P,.--. Q,--.- R,.-. S,... T,- U,..- V,...- W,.-- X,-..- Y,-.-- Z,--.. 0,----- 1,.---- 2,..--- 3,...-- 4,....- 5,..... 6,-.... 7,--... 8,---.. 9,----.