src/main/java/freemarker/core/_TimeZoneBuilder.java

/*
 * 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 freemarker.core;

import java.util.TimeZone;

/**
 * For internal use only; don't depend on this, there's no backward compatibility guarantee at all!
 */
public class _TimeZoneBuilder {

    private final String timeZoneId;

    public _TimeZoneBuilder(String timeZoneId) {
        this.timeZoneId = timeZoneId;
    }

    public TimeZone build() {
        TimeZone timeZone = TimeZone.getTimeZone(timeZoneId);
        if (timeZone.getID().equals("GMT") && !timeZoneId.equals("GMT") && !timeZoneId.equals("UTC")
                && !timeZoneId.equals("GMT+00") && !timeZoneId.equals("GMT+00:00") && !timeZoneId.equals("GMT+0000")) {
            throw new IllegalArgumentException("Unrecognized time zone: " + timeZoneId);
        }
        return timeZone;
    }

}