--- /dev/null
+/* Copyright (c) 2012. The SimGrid Team.
+ * All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+package kademlia;
+
+import java.util.ArrayList;
+import java.util.Collections;
+
+/**
+ * Answer to a "FIND_NODE" query. Contains the nodes closest to
+ * an id given.
+ */
+public class Answer {
+ /**
+ * Id of the node we're trying to find
+ */
+ private int destinationId;
+ /**
+ * Closest nodes in the answer.
+ */
+ private ArrayList<Contact> nodes;
+
+ /**
+ * Constructor
+ */
+ public Answer(int destinationId) {
+ this.destinationId = destinationId;
+ nodes = new ArrayList<Contact>();
+ }
+ /**
+ * Returns the destination id
+ */
+ int getDestinationId() {
+ return destinationId;
+ }
+ /**
+ * Returns the list of the nodes in the answer
+ */
+ ArrayList<Contact> getNodes() {
+ return nodes;
+ }
+ /**
+ * Returns the answer array size
+ */
+ int size() {
+ return nodes.size();
+ }
+ /**
+ * Remove an element from the answer.
+ */
+ public void remove(int index) {
+ nodes.remove(index);
+ }
+ /**
+ * Add a contact to the answer.
+ */
+ public void add(Contact contact) {
+ nodes.add(contact);
+ }
+ /**
+ * Merge the contents of this answer with another answer
+ */
+ public int merge(Answer answer) {
+ int nbAdded = 0;
+
+ for (Contact c: answer.getNodes()) {
+ if (!nodes.contains(c)) {
+ nbAdded++;
+ nodes.add(c);
+ }
+ }
+ Collections.sort(nodes);
+ //Trim the list
+ while (answer.size() > Common.BUCKET_SIZE) {
+ answer.remove(answer.size() - 1);
+ }
+ return nbAdded;
+ }
+ /**
+ * Returns if the destination has been found
+ */
+ public boolean destinationFound() {
+ if (nodes.size() < 1) {
+ return false;
+ }
+ Contact tail = nodes.get(0);
+ return tail.getDistance() == 0;
+ }
+ @Override
+ public String toString() {
+ return "Answer [destinationId=" + destinationId + ", nodes=" + nodes
+ + "]";
+ }
+
+}
