User I/O Problems

Question

Hello! I'm new to Java, but I've been usign C++ for a good long while now. Anyway. I'm writing a program for a professor that Asks the user for a letter and outputs the corresponding number on the telephone. This is to be nested inside a while-loop that allows the user to quit anytime they'd like. My problem is that when I run the program it accepts the letter from the user for translation into the telephone number, but with I try to get the user to enter 'y' or 'n' to quit the loop the program doesn't stop to query the user! My code is as follows:
import java.io.*;
public class Hwk1
     public static int translate(char c)
          int x;
          switch(c)
     case 'a': case 'b': case 'c': case 'A': case 'B': case 'C': x=2;
                    break;
     case 'd': case 'e': case 'f': case 'D': case 'E': case 'F': x=3;
                    break;
     case 'g': case 'h': case 'i': case 'G': case 'H': case 'I': x=4;
                    break;
     case 'j': case 'k': case 'l': case 'J': case 'K': case 'L': x=5;
                    break;
     case 'm': case 'n': case 'o': case 'M': case 'N': case 'O': x=6;
                    break;
     case 'p': case 'r': case 's': case 'P': case 'R': case 'S': x=7;
                    break;
     case 't': case 'u': case 'v': case 'T': case 'U': case 'V': x=8;
                    break;
     case 'w': case 'x': case 'y': case 'W': case 'X': case 'Y': x=9;
                    break;
               default: x=-1;
                    break;
          return x;
     public static void main(String[] args) throws IOException
          int c,d;
          char run='y';
          while(run=='y'||run=='Y')
               System.out.println("Enter a single letter:");
               c=System.in.read();
               d=translate((char)c);
          if(d!=-1)
System.out.println("The letter "+(char)c+" is
the number "+d+" on the telephone.");
          else
               System.out.println("The letter "+(char)c+" does
not correspond to a number on"+                               "the telephone.");
               System.out.println("Would you like to translate
another letter? (y/n)");
               run=System.in.read();
          System.out.println("Good Bye");
Sorry about the formatting problems, but the line of code I'm having problems with is run=System.in.read(); The second to the last line in the code. Thank you for all your help!!!

Answer 1

Unlike the case of C or C++, you should use the
java.io.InputStreamReader or BufferedReader for
iterating System.in.
BufferedReader br = new BufferedReader(new
InputStreamReader(System.in));
br.close();
Agreed. Otherwise both the letter you type, and the return key are both considered chars and the program gets confused. This is what your main method should look like:
  public static void main(String[] args) throws IOException {
    String c, run="y";
    int d;
    BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
    while(run.toLowerCase().equals("y")) {
      System.out.print("Enter a single letter:");
      c=br.readLine();
      d=translate(c.charAt(0));
      if(d!=-1) {
        System.out.println("The letter "+c+" is the number "+d+" on the telephone.");
      } else {
        System.out.println("The letter "+c+" does not correspond to a number on"+ "the telephone.");
      System.out.println("Would you like to translate another letter? (y/n)");
      run=br.readLine();
    br.close();
    System.out.println("Good Bye");