import java.security.MessageDigest;
public class MD5
{
    private MessageDigest md5;
    private static MD5 Instance;

    /** *//**
     * Constructs the MD5 object and sets the string whose MD5 is to be computed.
     *
     * @param inStr the <code>String</code> whose MD5 is to be computed
     */
    public synchronized static MD5 getMD5Instance()
    {
        if(Instance==null)
            Instance=new MD5();
        return Instance;
    }
    public MD5()
    {
        try{
            
            this.md5 = MessageDigest.getInstance("MD5");
        }
        catch (Exception e)
        {
            System.out.println(e.toString());
            e.printStackTrace();
        }
    }

    /** *//**
     * Computes the MD5 fingerprint of a string.
     *
     * @return the MD5 digest of the input <code>String</code>
     */
    public String compute(String inStr)
    {
    // convert input String to a char[]
    // convert that char[] to byte[]
    // get the md5 digest as byte[]
    // bit-wise AND that byte[] with 0xff
    // prepend "0" to the output StringBuffer to make sure that we don't end up with
    // something like "e21ff" instead of "e201ff"

    char[] charArray = inStr.toCharArray();
    byte[] byteArray = new byte[charArray.length];
    
    for (int i=0; i<charArray.length; i++)
        byteArray[i] = (byte) charArray[i];
    
    byte[] md5Bytes = this.md5.digest(byteArray);

        StringBuffer hexValue = new StringBuffer();

    for (int i=0; i<md5Bytes.length; i++)
   {
        int val = ((int) md5Bytes[i] ) & 0xff; 
        if (val < 16) hexValue.append("0");
        hexValue.append(Integer.toHexString(val));
    }

    return hexValue.toString();
    }
   
}