add getServiceName method

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

@@ -1,13 +1,93 @@
 package net.hyperic.sigar;
 
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.File;
+import java.io.FileReader;
+
 import java.util.ArrayList;
 import java.util.List;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
+import java.util.StringTokenizer;
 
 public class NetPortMap {
 
+    private static Map udpServices = null;
+    private static Map tcpServices = null;
+
+    private static void parseServices(String type, Map services) {
+        File file = new File("/etc/services");
+        if (!file.exists()) {
+            return;
+        }
+
+        BufferedReader reader = null;
+
+        try {
+            reader = new BufferedReader(new FileReader(file));
+            String line;
+            while ((line = reader.readLine()) != null) {
+                String name, protocol;
+                Long port;
+
+                line = line.trim();
+                if ((line.length() == 0) || (line.charAt(0) == '#')) {
+                    continue;
+                }
+
+                StringTokenizer st = new StringTokenizer(line, " \t/#");
+                if (st.countTokens() < 3) {
+                    continue;
+                }
+                name = st.nextToken().trim();
+                String pnum = st.nextToken().trim();
+                protocol = st.nextToken().trim();
+                if (!type.equals(protocol)) {
+                    continue;
+                }
+                services.put(Long.valueOf(pnum), name);
+            }
+        } catch (IOException e) {
+            return;
+        } finally {
+            if (reader != null) {
+                try {
+                    reader.close();
+                } catch (IOException e) { }
+            }
+        }
+    }
+
+    public static String getServiceName(String protocol, long port) {
+        if (protocol.equals("tcp")) {
+            return getTcpServiceName(port);
+        }
+        else if (protocol.equals("udp")) {
+            return getUdpServiceName(port);
+        }
+        else {
+            return String.valueOf(port);
+        }
+    }
+
+    public static String getTcpServiceName(long port) {
+        if (tcpServices == null) {
+            tcpServices = new HashMap();
+            parseServices("tcp", tcpServices);
+        }
+        return (String)tcpServices.get(new Long(port));
+    }
+
+    public static String getUdpServiceName(long port) {
+        if (udpServices == null) {
+            udpServices = new HashMap();
+            parseServices("udp", udpServices);
+        }
+        return (String)udpServices.get(new Long(port));
+    }
+
     /**
      * Map listening tcp ports to connected remote addresses.
      * key == Listening tcp port on the local machine.