StringUtil

import java.util.Random;
import java.util.UUID;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.Validate;

public class StringUtil {

public final static String EMPTY = "";

public final static boolean isEmpty(String s) {
return s == null || s.trim().equals(EMPTY);
}

public final static String vague(String s, int begin, int end) {
if (isEmpty(s)) {
return s;
}

if (s.length() <= begin + end) {
return s;
}
char[] chars = s.toCharArray();
for (int i = begin; i < chars.length - end; i++) {
chars[i] = '*';
}

return new String(chars);
}

public final static String uuid() {
String uuid = UUID.randomUUID().toString().replace("-", "");
return uuid;
}

// public final static String myuid() {
// UUID uuid = Generators.timeBasedGenerator().generate();
// long mostSigBits = uuid.getMostSignificantBits();
// long leastSigBits = uuid.getLeastSignificantBits();
// return (
// digits(mostSigBits, 4) +
// digits(mostSigBits >> 16, 4) +
// digits(mostSigBits >> 32, 8) +
// digits(leastSigBits >> 48, 4) +
// digits(leastSigBits, 12)
// );
// }

public final static boolean in(String param, String... factor) {
if (null != factor && factor.length != 0) {
for (String f : factor) {
if (param.equals(f)) {
return true;
}
}
}
return false;
}

private static final Random random = new Random();

public static String random(int bytesLength) {
Validate.isTrue(bytesLength > 0, "numBytes argument must be a positive integer (1 or larger)", bytesLength);
byte[] bytes = new byte[bytesLength];
random.nextBytes(bytes);
String s = encodeBase64(bytes);
return s;
}

public static String encodeBase64(byte[] bytes) {
return Base64.encodeBase64String(bytes);
}

public static byte[] decodeBase64(String cipher) {
return Base64.decodeBase64(cipher);
}

}