@Component
public class WrokTask {
@Autowired
private IJobService jobService;
private static String serviceName=“provider”;
@Scheduled(fixedDelay = 5000)
public void doWork(){
if (IPV4Util.ipCompare(this.jobService.serviceUrl(serviceName))) {
System.out.println(serviceName+“服务,地址为：”+IPV4Util.getIpAddress()+",正在执行task任务");
}
}
}
定时任务中我们可以看到this.jobService.serviceUrl方法，这个方法的作用则是获取SpringCloud集群中服务信息，IPV4Util.ipCompare这个作用就是将当前服务IP和集群所有IP进行对比，如果当前服务IP是集群服务IP最小则返回true，反之返回false。
接下来我们再看一下，如果来获取SpringCloud集群信息：
@Service
public class JobServiceImpl implements IJobService {
@Autowired
private DiscoveryClient discoveryClient;
@Override
public List serviceUrl(String serviceName) {
List serviceInstanceList = discoveryClient.getInstances(serviceName);
List urlList = new ArrayList();
if (CollectionUtils.isNotEmpty(serviceInstanceList)) {
serviceInstanceList.forEach(si -> {
urlList.add(si.getUri());
});
}
return urlList;
}
}
其实主要还是用到DiscoveryClient类中方法，我们就可以很轻松获取到集群信息。
最后我们再来看看IPV4Util这个工具类到底是怎么进行对比的呢？
public class IPV4Util {
public static long ipToLong(String ipAddress) {
long result = 0;
String[] ipAddressInArray = ipAddress.split(".");
for (int i = 3; i >= 0; i–) {
long ip = Long.parseLong(ipAddressInArray[3 - i]);
// left shifting 24,16,8,0 and bitwise OR
// 1. 192 << 24
// 1. 168 << 16
// 1. 1 << 8
// 1. 2 << 0
result |= ip << (i * 8);
}
return result;
}
public static String longToIp(long ip) {
StringBuilder result = new StringBuilder(15);
for (int i = 0; i < 4; i++) {
result.insert(0, Long.toString(ip & 0xff));
if (i < 3) {
result.insert(0, ‘.’);
}
ip = ip >> 8;
}
return result.toString();
}
public static String longToIp2(long ip) {
return ((ip >> 24) & 0xFF) + “.” + ((ip >> 16) & 0xFF) + “.” + ((ip >> 8) & 0xFF) + “.” + (ip & 0xFF);
}
public static String getIpAddress() {
try {
for (Enumeration enumNic = NetworkInterface.getNetworkInterfaces();
enumNic.hasMoreElements(); ) {
NetworkInterface ifc = enumNic.nextElement();
if (ifc.isUp()) {
for (Enumeration enumAddr = ifc.getInetAddresses();
enumAddr.hasMoreElements(); ) {
InetAddress address = enumAddr.nextElement();
if (address instanceof Inet4Address && !address.isLoopbackAddress()) {
return address.getHostAddress();
}
}
}
}
return InetAddress.getLocalHost().getHostAddress();
} catch (IOException e) {
//log.warn(“Unable to find non-loopback address”, e);
e.printStackTrace();
}
return null;
}
/**
- 对比方法
