MD5工具类

import java.security.MessageDigest;  
import java.security.NoSuchAlgorithmException;  
  
public class MD5Tool {  
  
    public static String md5(String string) {  
        byte[] hash;  
        try {  
            hash = MessageDigest.getInstance("MD5").digest(string.getBytes("UTF-8"));  
        } catch (NoSuchAlgorithmException e) {  
            throw new RuntimeException("Huh, MD5 should be supported?", e);  
        } catch (UnsupportedEncodingException e) {  
            throw new RuntimeException("Huh, UTF-8 should be supported?", e);  
        }  
  
        StringBuilder hex = new StringBuilder(hash.length * 2);  
        for (byte b : hash) {  
            if ((b & 0xFF) < 0x10) hex.append("0");  
            hex.append(Integer.toHexString(b & 0xFF));  
        }  
        return hex.toString();  
    }  
}