Update 0102.二叉树的层序遍历.md

Add Java implementation for leetcode 116

problems/0102.二叉树的层序遍历.md

@@ -1205,6 +1205,35 @@ public:
 };
 ```
 
+java代码：
+
+```java
+class Solution {
+    public Node connect(Node root) {
+	Queue<Node> tmpQueue = new LinkedList<Node>();
+	if (root != null) tmpQueue.add(root);
+		
+	while (tmpQueue.size() != 0){
+	    int size = tmpQueue.size();
+            
+            Node cur = tmpQueue.poll();
+            if (cur.left != null) tmpQueue.add(cur.left);
+            if (cur.right != null) tmpQueue.add(cur.right);
+            
+	    for (int index = 1; index < size; index++){
+		Node next = tmpQueue.poll();
+		if (next.left != null) tmpQueue.add(next.left);
+		if (next.right != null) tmpQueue.add(next.right);
+                
+                cur.next = next;
+                cur = next;
+	    }
+	}
+        
+        return root;
+    }
+}
+```
 
 python代码：