added java example

examples/java/ZeroTierHelloWorld/src/zerotier/Address.java

@@ -0,0 +1,84 @@
+package zerotier;
+
+import java.math.BigInteger;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.UnknownHostException;
+import java.util.regex.Pattern;
+
+/*
+
+The ZTAddress object is merely a convenience object for moving address information
+across the JNI memory border.
+
+*/
+
+public class Address
+{
+    // int -> byte array
+    static public byte[] toIPByteArray(long addr){
+        return new byte[]{(byte)addr,(byte)(addr>>>8),(byte)(addr>>>16),(byte)(addr>>>24)};
+    }
+
+    // byte array -> int
+    long toIPInt(String _addr) {
+        long result = 0;
+        for(String part: _addr.split(Pattern.quote("."))) {
+            result = result << 8;
+            result |= Integer.parseInt(part);
+        }
+        return result;
+    }
+
+    public int port;
+    public int Port() {
+        return port;
+    }
+
+    public long _rawAddr;
+    public String Address()
+    {
+        try {
+            return InetAddress.getByAddress(toIPByteArray(_rawAddr)).getHostAddress();
+        } catch (UnknownHostException e) {
+            // should never happen
+            return null;
+        }
+    }
+
+    public String toString() {
+        return Address() + ":" + Port();
+    }
+
+    public Address()
+    {
+        port = -1;
+        _rawAddr = -1;
+    }
+
+    public Address(String _addr, int _port)
+    {
+        _rawAddr = toIPInt(_addr);
+        port = _port;
+    }
+
+    public void ZTAddress(InetSocketAddress ins)
+    {
+        port = ins.getPort();
+        _rawAddr = toIPInt(ins.getAddress().getHostAddress());
+    }
+
+    public InetSocketAddress ToInetSocketAddress() throws IllegalArgumentException {
+        InetSocketAddress sock_addr = null;
+        try {
+            sock_addr = new InetSocketAddress(Address(), port);
+        } catch (IllegalArgumentException e) {
+            e.printStackTrace();
+        }
+        return sock_addr;
+    }
+
+    public boolean isValid() {
+        return port != -1 && !Address().startsWith("-1.-1.-1.-1/-1");
+    }
+}