Add server for running AVLSearchTree

app/src/main/java/ch/nuth/zhaw/exbox/RankingAVLTreeServer.java

@@ -0,0 +1,38 @@
+package ch.nuth.zhaw.exbox;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class RankingAVLTreeServer implements CommandExecutor {
+
+    public Tree<Competitor> createTree(String rankingText) {
+        SortedBinaryTree<Competitor> result = new AVLSearchTree<>();
+        List<Competitor> competitors = new RankingListServer().createList(rankingText);
+
+        for (Competitor competitor : competitors) {
+            result.add(competitor);
+        }
+
+        return result;
+    }
+
+    public String createSortedText(Tree<Competitor> competitorTree) {
+        AtomicInteger rank = new AtomicInteger(1);
+        StringBuilder sb = new StringBuilder();
+
+        competitorTree.traversal().inorder(
+            (competitor) -> {
+                competitor.setRank(rank.getAndIncrement());
+                sb.append(competitor);
+                sb.append(System.lineSeparator());
+            });
+
+        return sb.toString();
+    }
+
+    public String execute(String rankingList) {
+        Tree<Competitor> competitorTree = createTree(rankingList);
+        return "Rangliste (Tree)\n" + createSortedText(competitorTree) + "\n\n" +
+            "Height: " + competitorTree.height() + "\nSize: " + competitorTree.size();
+    }
+}