import java.nio.charset.Charset;

public class StringUtil
{
 public static byte[] dataToByteArray(String s)
 {
 byte[] btAryData = new byte[s.length()];
 for (int i = 0; i < btAryData.length; i++)
 {
 btAryData[i] = (byte)s.charAt(i);
 }
 return btAryData;
 }

 public static String toHexString(String src)
 {
 StringBuilder sb = new StringBuilder();
 for (int i = 0; i < src.length(); i++)
 {
 char c = src.charAt(i);
 sb.append(Integer.toHexString(c));
 }
 return sb.toString();
 }

 public static String toCharStr(String hexStr)
 {
 if(hexStr.length() % 2 == 0)
 {
 StringBuilder sb = new StringBuilder();
 for (int i = 0; i < hexStr.length(); i += 2)
 {
 String s = hexStr.substring(i , i+2);
 int v = Integer.valueOf(s, 16);
 sb.append((char)v);
 }
 return sb.toString();
 }
 return "";
 }

 public static String byteArrayToString(byte[] ar)
 {
 return new String(ar, Charset.forName("US-ASCII"));
 }

 public static int dataLength(String s)
 {
 return s.length();
 }

}