map listening tcp ports to connected remote addresses

bindings/java/src/net/hyperic/sigar/NetPortMap.java

@@ -0,0 +1,71 @@
+package net.hyperic.sigar;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+public class NetPortMap {
+
+    /**
+     * Map listening tcp ports to connected remote addresses.
+     * key == Listening tcp port on the local machine.
+     * value == List of connected remote addresses.
+     */
+    public static Map getTcpConnections(Sigar sigar)
+        throws SigarException {
+
+        int flags =
+            NetFlags.CONN_SERVER | NetFlags.CONN_TCP;
+
+        Map map = new HashMap();
+
+        NetConnection[] connections =
+            sigar.getNetConnectionList(flags);
+
+        //first pass, get listening port numbers
+        for (int i=0; i<connections.length; i++) {
+            NetConnection conn = connections[i];
+            Long port = new Long(conn.getLocalPort());
+            List addresses = (List)map.get(port);
+
+            if (addresses == null) {
+                addresses = new ArrayList();
+                map.put(port, addresses);
+            }
+        }
+
+        //second pass, get addresses connected to listening ports
+        flags = NetFlags.CONN_CLIENT | NetFlags.CONN_TCP;
+        connections = sigar.getNetConnectionList(flags);
+
+        for (int i=0; i<connections.length; i++) {
+            NetConnection conn = connections[i];
+            Long port = new Long(conn.getLocalPort());
+            List addresses = (List)map.get(port);
+
+            if (addresses == null) {
+                continue;
+            }
+
+            addresses.add(conn.getRemoteAddress());
+        }
+
+        return map;
+    }
+
+    public static void main(String[] args) throws Exception {
+        Sigar sigar = new Sigar();
+        Map ports = getTcpConnections(sigar);
+
+        for (Iterator it = ports.entrySet().iterator();
+             it.hasNext();)
+        {
+            Map.Entry entry = (Map.Entry)it.next();
+            Long port = (Long)entry.getKey();
+            List addresses = (List)entry.getValue();
+            System.out.println(port + "=" + addresses);
+        } 
+    }
+}