import java.net.*;
import java.util.*;
import java.security.*;
import org.apache.log4j.Logger;
/**
* 產生唯一GUID
*/
public class RandomGUID extends Object {
public String valueBeforeMD5 =
"";
public String valueAfterMD5 =
"";
private static Random myRand;
private static SecureRandom mySecureRand;
static Logger logger = Logger.getLogger(RandomGUID.class);
static {
mySecureRand =
new SecureRandom();
long secureInitializer = mySecureRand.nextLong();
myRand =
new Random(secureInitializer);
}
/**
* 生成32位GUID码
* @return
*/
static public String
generatorGUID() {
RandomGUID myGUID =
new RandomGUID();
return myGUID.toString();
}
public RandomGUID() {
getRandomGUID(
false);
}
public RandomGUID(
boolean secure) {
getRandomGUID(secure);
}
private void getRandomGUID(
boolean secure) {
MessageDigest md5 =
null;
StringBuffer sbValueBeforeMD5 =
new StringBuffer();
try {
md5 = MessageDigest.getInstance(
"MD5");
}
catch (NoSuchAlgorithmException e) {
logger.error(
"Error: " + e);
}
try {
InetAddress id = InetAddress.getLocalHost();
long time = System.currentTimeMillis();
long rand =
0;
if (secure) {
rand = mySecureRand.nextLong();
}
else {
rand = myRand.nextLong();
}
sbValueBeforeMD5.append(id.toString());
sbValueBeforeMD5.append(
":");
sbValueBeforeMD5.append(Long.toString(time));
sbValueBeforeMD5.append(
":");
sbValueBeforeMD5.append(Long.toString(rand));
valueBeforeMD5 = sbValueBeforeMD5.toString();
md5.update(valueBeforeMD5.getBytes());
byte[] array = md5.digest();
StringBuffer sb =
new StringBuffer();
for (
int j =
0; j < array.length; ++j) {
int b = array[j] &
0xFF;
if (b <
0x10)
sb.append(
'0');
sb.append(Integer.toHexString(b));
}
valueAfterMD5 = sb.toString();
}
catch (UnknownHostException e) {
logger.error(
"Error:" + e);
}
}
public String
toString() {
String raw = valueAfterMD5.toUpperCase();
StringBuffer sb =
new StringBuffer();
sb.append(raw.substring(
0,
8));
sb.append(raw.substring(
8,
12));
sb.append(raw.substring(
12,
16));
sb.append(raw.substring(
16,
20));
sb.append(raw.substring(
20));
return sb.toString();
}
public static void main(String[] args) {
RandomGUID myGUID =
new RandomGUID(
true);
logger.error(
"Seeding String=" + myGUID.valueBeforeMD5);
logger.error(
"rawGUID=" + myGUID.valueAfterMD5);
logger.error(
"RandomGUID=" + myGUID.toString());
}
}
转载于:https://www.cnblogs.com/bilaisheng/p/10211016.html
相关资源：java代码生成GUID
