nl.renarj.jasdb.service.MachineGuidGenerator Maven / Gradle / Ivy
package nl.renarj.jasdb.service;
import nl.renarj.jasdb.core.exceptions.JasDBStorageException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.Enumeration;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicLong;
/**
* @author Renze de Vries
*/
@Component
public class MachineGuidGenerator implements IdGenerator {
private static final Logger LOG = LoggerFactory.getLogger(MachineGuidGenerator.class);
private static final long machineId = generateMachineId();
private static final AtomicLong startId = new AtomicLong(System.currentTimeMillis());
@Override
public String generateNewId() throws JasDBStorageException {
long sequentialId = startId.incrementAndGet();
return new UUID(machineId, sequentialId).toString();
}
private static long generateMachineId() {
try {
Enumeration networkInterfaceEnumeration = NetworkInterface.getNetworkInterfaces();
while(networkInterfaceEnumeration.hasMoreElements()) {
NetworkInterface networkInterface = networkInterfaceEnumeration.nextElement();
if(!networkInterface.isLoopback() && networkInterface.getHardwareAddress() != null) {
byte[] hardwareAddress = networkInterface.getHardwareAddress();
long machineId = hardwareAddress[0] & 0xFF;
for (int i = 1; i < 6; ++i) {
machineId = (machineId << 8) | (hardwareAddress[i] & 0xFF);
}
return machineId;
}
}
} catch(SocketException e) {
LOG.error("Unable to determine machineId", e);
}
LOG.info("Could not determine machineId, using system time for machineId");
return System.nanoTime();
}
}