Add simple Key generation for Watcher ws client

zeppelin-zengine/src/main/java/org/apache/zeppelin/util/WatcherSecurityKey.java

@@ -0,0 +1,35 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zeppelin.util;
+
+import java.util.UUID;
+
+/**
+ * Simple implementation of a auto-generated key for websocket watcher.
+ * This is a LAZY implementation, we might want to update this later on :)
+ */
+public class WatcherSecurityKey {
+  public static final String HTTP_HEADER = "X-Watcher-Key";
+  private static final String KEY = UUID.randomUUID().toString();
+
+  protected WatcherSecurityKey() {}
+
+  public static String getKey() {
+    return KEY;
+  }
+
+}