IpFetcher: format.

Author: MarcFraile

src/main/java/cloudgene/mapred/util/IpFetcher.java

@@ -10,74 +10,77 @@
 import java.util.logging.Logger;
 
 /**
- * Provides the static method fetchServerIp(), which returns this server's IP.
+ * Provides the static method {@link #fetchServerIp()}, which returns this
+ * server's IP.
  */
 public final class IpFetcher {
 
-    private IpFetcher() {}
+	private IpFetcher() {}
 
-    private static String serverIp = null;
+	private static String serverIp = null;
 
-    /**
-     * Loops through the system's reported IP addresses and returns the first IPv4 external address. If anything goes
-     * wrong, returns null.
-     *
-     * Note that the returned IP is only guaranteed to be visible in the local network link. E.g., a router in the
-     * way could map this IP to a different one.
-     */
-    private static String fetchSystemIpV4() {
-        try {
-            Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
-            while (networkInterfaces.hasMoreElements()) {
-                NetworkInterface iface = networkInterfaces.nextElement();
+	/**
+	 * Loops through the system's reported IP addresses and returns the first IPv4
+	 * external address. If anything goes wrong, returns null.
+	 *
+	 * Note that the returned IP is only guaranteed to be visible in the local
+	 * network link. E.g., a router in the way could map this IP to a different one.
+	 */
+	private static String fetchSystemIpV4() {
+		try {
+			Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
+			while (networkInterfaces.hasMoreElements()) {
+				NetworkInterface iface = networkInterfaces.nextElement();
 
-                if (!iface.isUp() || iface.isLoopback() || iface.isVirtual() || iface.isPointToPoint()) {
-                    continue;
-                }
+				if (!iface.isUp() || iface.isLoopback() || iface.isVirtual() || iface.isPointToPoint()) {
+					continue;
+				}
 
-                Enumeration<InetAddress> addresses = iface.getInetAddresses();
-                while (addresses.hasMoreElements()) {
-                    InetAddress addr = addresses.nextElement();
+				Enumeration<InetAddress> addresses = iface.getInetAddresses();
+				while (addresses.hasMoreElements()) {
+					InetAddress addr = addresses.nextElement();
 
-                    if (addr instanceof Inet4Address && !addr.isLoopbackAddress() && !addr.isLinkLocalAddress()) {
-                        return addr.getHostAddress();
-                    }
-                }
-            }
-            return null;
-        } catch (Exception e) {
-            return null;
-        }
-    }
+					if (addr instanceof Inet4Address && !addr.isLoopbackAddress() && !addr.isLinkLocalAddress()) {
+						return addr.getHostAddress();
+					}
+				}
+			}
+			return null;
+		} catch (Exception e) {
+			return null;
+		}
+	}
 
-    /**
-     * Does the actual IP fetching work behind fetchServerIp(), see comments there.
-     */
-    private static String actuallyFetchTheIp() {
-        Logger.getLogger("com.amazonaws").setLevel(Level.SEVERE); // Avoid warning dumps if we're not in AWS
-        String ec2Ip = EC2MetadataUtils.getPrivateIpAddress();
-        if (ec2Ip != null) return ec2Ip;
+	/**
+	 * Does the actual IP fetching work behind fetchServerIp(), see comments there.
+	 */
+	private static String actuallyFetchTheIp() {
+		Logger.getLogger("com.amazonaws").setLevel(Level.SEVERE); // Avoid warning dumps if we're not in AWS
+		String ec2Ip = EC2MetadataUtils.getPrivateIpAddress();
+		if (ec2Ip != null) {
+			return ec2Ip;
+		}
 
-        String localIp = fetchSystemIpV4();
-        if (localIp != null) return localIp;
+		String localIp = fetchSystemIpV4();
+		if (localIp != null) {
+			return localIp;
+		}
 
-        throw new IllegalStateException("Failed to obtain a valid server IPv4 address from available metadata.");
-    }
+		throw new IllegalStateException("Failed to obtain a valid server IPv4 address from available metadata.");
+	}
 
-    /**
-     * Fetches this server's IPv4, as visible from its local network.
-     * In an AWS environment, it uses the EC2 metadata service to get the "private IP" that is valid in the local VPC.
-     * Otherwise, attempts to get the address from the system.
-     * Raises an IllegalStateException if no valid IPv4 can be obtained.
-     *
-     * Results are cached for the lifetime of the application.
-     *
-     * @return This server's IPv4, as visible from its local network.
-     */
-    public static String fetchServerIp() {
-        if (serverIp == null) {
-            serverIp = actuallyFetchTheIp();
-        }
-        return serverIp;
-    }
+	/**
+	 * Fetches this server's IPv4, as visible from its local network. In an AWS
+	 * environment, it uses the EC2 metadata service to get the "private IP" that is
+	 * valid in the local VPC. Otherwise, attempts to get the address from the
+	 * system. Raises an IllegalStateException if no valid IPv4 can be obtained.
+	 *
+	 * Results are cached for the lifetime of the application.
+	 */
+	public static String fetchServerIp() {
+		if (serverIp == null) {
+			serverIp = actuallyFetchTheIp();
+		}
+		return serverIp;
+	}
 }