Question

This a code for converting hex to string but it works fine until size of the string doesn’t exceeds 62 characters?

public static String hexToString(String hex)
        {       
           StringBuilder output = new StringBuilder();
           for (int i = 0; i < hex.length(); i+=2)
           {
            String str = hex.substring(i, i+2);
            output.append((char)Integer.parseInt(str, 16));
           }
           return(output.toString());
        }

java.lang.StringIndexOutOfBoundsException: String index out of range:
62
at java.lang.String.substring(Unknown Source)
at HEX.hexToString(HEX.java:36)
at HEX.main(HEX.java:56)

Answer 1

You will face this problem only when you have odd number of characters in your string. Fix your function as follows:

public static String hexToString(String hex)
    {       
       StringBuilder output = new StringBuilder();
       String str = "";
       for (int i = 0; i < hex.length(); i+=2)
       {

        if(i+2 < hex.length()){
            str = hex.substring(i, i+2);
        }else{
            str = hex.substring(i, i+1);
        }
        output.append((char)Integer.parseInt(str, 16));
       }
       return(output.toString());
    }