package open.dolphin.util;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.UUID;
public class GUIDGenerator {
/** Cached per JVM server IP. */
private static String hexServerIP = null;
// initialise the secure random instance
private static final java.security.SecureRandom seeder = new java.security.SecureRandom();
/**
* A 32 byte GUID generator (Globally Unique ID). These artificial keys
* SHOULD <strong>NOT </strong> be seen by the user, not even touched by the
* DBA but with very rare exceptions, just manipulated by the database and
* the programs.
*
* Usage: Add an id field (type java.lang.String) to your EJB, and add
* setId(XXXUtil.generateGUID(this)); to the ejbCreate method.
* @param o
* @return
*/
public static String generate(Object o) {
StringBuilder tmpBuffer = new StringBuilder(16);
if (hexServerIP == null) {
java.net.InetAddress localInetAddress;
try {
// get the inet address
localInetAddress = java.net.InetAddress.getLocalHost();
} catch (java.net.UnknownHostException uhe) {
System.err.println("KingAppoUtil: Could not get the local IP address using InetAddress.getLocalHost()!");
// todo: find better way to get around this...
uhe.printStackTrace(System.err);
// Mavericks対応
//return null;
String uuid = UUID.randomUUID().toString();
uuid = uuid.replaceAll("-", "");
if(uuid.length() != 32) {
SimpleDateFormat effectiveFormat = new SimpleDateFormat("yyyyMMddHHmmssSSS");
uuid = effectiveFormat.format(new Date()) + "000000000000000";
}
return uuid;
}
byte serverIP[] = localInetAddress.getAddress();
hexServerIP = hexFormat(getInt(serverIP), 8);
}
String hashcode = hexFormat(System.identityHashCode(o), 8);
tmpBuffer.append(hexServerIP);
tmpBuffer.append(hashcode);
long timeNow = System.currentTimeMillis();
int timeLow = (int) timeNow & 0xFFFFFFFF;
int node = seeder.nextInt();
StringBuilder guid = new StringBuilder(32);
guid.append(hexFormat(timeLow, 8));
guid.append(tmpBuffer.toString());
guid.append(hexFormat(node, 8));
return guid.toString();
}
private static int getInt(byte bytes[]) {
int i = 0;
int j = 24;
for (int k = 0; j >= 0; k++) {
int l = bytes[k] & 0xff;
i += l << j;
j -= 8;
}
return i;
}
private static String hexFormat(int i, int j) {
String s = Integer.toHexString(i);
return padHex(s, j) + s;
}
private static String padHex(String s, int i) {
StringBuilder tmpBuffer = new StringBuilder();
if (s.length() < i) {
for (int j = 0; j < i - s.length(); j++) {
tmpBuffer.append('0');
}
}
return tmpBuffer.toString();
}
}