added a method to test if hostnames are legitimate

src/tools/TestLegitIP.java

@@ -0,0 +1,28 @@
+package tools;
+
+/** Test if IP are legitimate.
+ * @author	Louis Royer
+ * @author	Flavien Haas
+ * @author	JS Auge
+ * @version	1.0
+ */
+public class TestLegitIP {
+
+	public boolean TestIP(String hostname) {
+    if(hostname.equals("localhost")){
+      return true;
+    }
+    else{
+      String[] ipArray = hostname.split("\\.");
+      if(ipArray.length != 4){
+        return false;
+      }
+      for(int i= 0; i < ipArray.length; i++){
+        if((Integer.parseInt(ipArray[i]) > 255) || (Integer.parseInt(ipArray[i]) < 0)){
+          return false;
+        }
+      }
+    }
+    return true;
+	}
+}