tapestry-framework/src/java/org/apache/tapestry/engine/EngineUtils.java

// Copyright 2005 The Apache Software Foundation
//
// Licensed 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.tapestry.engine;

import org.apache.tapestry.web.WebRequest;

/**
 * Utilities needed by engine services and etc.
 * 
 * @author Howard M. Lewis Ship
 * @since 4.0
 */
public final class EngineUtils
{

    /* defeat instantiation */
    private EngineUtils() { }
    
    /**
     * Invoked by to see if an absolute URL is needed (because a specific scheme, server or port
     * was indicated that does not match the incoming request).
     * 
     * @param scheme
     *            the desired URL scheme, or null
     * @param server
     *            the desired URL server name, or null
     * @param port
     *            the desired URL port, or 0
     * @param request
     *            the request to check against
     * @return true if absolute URL is needed, false otherwise
     */
    public static boolean needAbsoluteURL(String scheme, String server, int port, WebRequest request)
    {
        if (scheme != null && !scheme.equals(request.getScheme())) return true;

        if (server != null && !server.equals(request.getServerName()))
            return true;

        if (port != 0 && port != request.getServerPort()) return true;

        return false;
    }

}