java byte[]转16进制字符串

* Convert byte[] to hex string.这里我们可以将byte转换成int，然后利用Integer.toHexString(int)来转换成16进制字符串。  
 * @param src byte[] data  
 * @return hex string  
 */     
public static String bytesToHexString(byte[] src){  
    StringBuilder stringBuilder = new StringBuilder("");  
    if (src == null || src.length <= 0) {  
        return null;  
    }  
    for (int i = 0; i < src.length; i++) {  
        int v = src[i] & 0xFF;  
        String hv = Integer.toHexString(v);  
        if (hv.length() < 2) {  
            stringBuilder.append(0);  
        }  
        stringBuilder.append(hv);  
    }  
    return stringBuilder.toString();  
}