GUACAMOLE-760: Add support for configuring server timezone.

guacamole-ext/src/main/java/org/apache/guacamole/properties/TimeZoneGuacamoleProperty.java

@@ -0,0 +1,43 @@
+/*
+ * 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.guacamole.properties;
+
+import java.util.TimeZone;
+import org.apache.guacamole.GuacamoleException;
+
+/**
+ * A GuacamoleProperty whose value is a TimeZone.
+ */
+public abstract class TimeZoneGuacamoleProperty
+        implements GuacamoleProperty<TimeZone> {
+    
+    @Override
+    public TimeZone parseValue(String value) throws GuacamoleException {
+        
+        // Nothing in, nothing out
+        if (value == null || value.isEmpty())
+            return null;
+        
+        // Attempt to return the TimeZone of the provided string value.
+        return TimeZone.getTimeZone(value);
+        
+    }
+    
+}