more IPv6 fixes

readme.txt

@@ -136,7 +136,7 @@ Please clone our code and help with development!
 The code is licensed under the GPL v2.
 
 Compiling YaCy:
-- you need java 1.6 and ant
+- you need java 1.7 and ant
 - just compile: "ant clean all" - then you can "./startYACY.sh"
 - create a release tarball: "ant dist"
 - create a Mac OS release: "ant distMacApp" (works only on a Mac)

source/net/yacy/cora/protocol/Domains.java

@@ -1043,7 +1043,8 @@ public class Domains {
     }
 
     public static Set<String> myPublicIPs() {
-        Set<String> h = new HashSet<>(publicIPv4HostAddresses.size() + publicIPv6HostAddresses.size());
+        // use a LinkedHashSet to get an order of IPs where the IPv4 are preferred to get a better compatibility with older implementations
+        Set<String> h = new LinkedHashSet<>(publicIPv4HostAddresses.size() + publicIPv6HostAddresses.size());
         for (InetAddress i: publicIPv4HostAddresses) h.add(i.getHostAddress());
         for (InetAddress i: publicIPv6HostAddresses) h.add(i.getHostAddress());
         return h;

source/net/yacy/cora/protocol/ftp/FTPClient.java

@@ -2082,7 +2082,7 @@ public class FTPClient {
 
         // save ip address in high byte order
         // byte[] Bytes = LocalIp.getAddress();
-        final byte[] b = Domains.myPublicLocalIP().getAddress();
+        final byte[] b = Domains.myPublicIPv4().iterator().next().getAddress();
 
         // bytes greater than 127 should not be printed as negative
         final short[] s = new short[4];