ciao.
ho il seguente errore:
unreported exception java.security.NoSuchAlgorithmException; must be caught or declared to be thrown
String sha1_ad1 = Sha256.SHA1("abc");

codice:
import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.io.IOException;
 
public class Sha256 {
 
    private static String convertToHex(byte[] data) 
    {
    	try
    	{
    		StringBuffer buf = new StringBuffer();
	        for (int i = 0; i < data.length; i++) {
	        	int halfbyte = (data[i] >>> 4) & 0x0F;
	        	int two_halfs = 0;
	        	do {
		            if ((0 <= halfbyte) && (halfbyte <= 9))
		                buf.append((char) ('0' + halfbyte));
		            else
		            	buf.append((char) ('a' + (halfbyte - 10)));
		            halfbyte = data[i] & 0x0F;
	        	} while(two_halfs++ < 1);
	        }
	        return buf.toString();
    	}
        catch(Exception e)
        {
        	return null;
        }
    }
 
    public static String SHA1(String text) throws NoSuchAlgorithmException, UnsupportedEncodingException
	{
	  	try
	  	{
	  		MessageDigest md;
			md = MessageDigest.getInstance("SHA-256");
			byte[] sha1hash = new byte[40];
			md.update(text.getBytes("iso-8859-1"), 0, text.length());
			sha1hash = md.digest();
			return convertToHex(sha1hash);
	  	}
	  	catch (Exception e)
	  	{
	  		return null;
	  	}
    }
    
    public static void main(String[] args) {
    	String sha1_ad1 = Sha256.SHA1("abc");	
    	System.out.println(sha1_ad1);
    	//String s = "abc";
    	//Sha256 sha = new Sha256();
    	//String sha1_ad1 = sha.SHA1(s);
    }
}
Per favore, potete aiutarmi.
Grazie
Ciao
Alberto