org.nbnResolving.views.BaseView Maven / Gradle / Ivy

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/* *********************************************************************
 * Abstract Class BaseView
 * 
 * Copyright (c) 2011-2012, German National Library/Deutsche Nationalbibliothek
 * Adickesallee 1, D-60322 Frankfurt am Main, Federal Republic of Germany 
 *
 * This program is free software.
 * 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.
 * 
 * Thomas Haidlas -- German National Library
 * Kadir Karaca Kocer -- German National Library
 **********************************************************************/

/* ********************************************************************
 * CHANGELOG:
 * 
 * 2012-04-03 Port to Maven by Timo Heck & Karaca Kocer
 * Created on 2011-12-12 by Karaca Kocer
 ********************************************************************/

package org.nbnResolving.views;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.view.AbstractView;

/**
 * Abstract Class to unify the HTTP-Header/Cache Setting-Code for all used
 * different views.
 * See HTTP 1.1 specification for details.
 * 
 * @see org.springframework.web.servlet.view.AbstractView
 * @see javax.servlet.http.HttpServletResponse
 * {@link "http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html"}
 * @author Kadir Karaca Kocer, German National Library
 */
public abstract class BaseView extends AbstractView {
	protected String ENCODING = "UTF-8" ; //default encoding UTF-8 should be used if not overwritten
	protected int    cacheIntervall = 15; //Max Age of cache in minutes. Default 15 minutes
	//protected String server = "";
	
	@Override
	protected void prepareResponse(HttpServletRequest request, HttpServletResponse response) {
		response.setContentType(getContentType());
		response.setCharacterEncoding(getENCODING());
		long now = System.currentTimeMillis();
		response.addDateHeader("Date", now);
		response.addDateHeader("Last-Modified", now);
		if (this.cacheIntervall < 1) {
			response.addHeader("Pragma", "no-cache");
			response.addHeader("Cache-Control", "no-cache, no-store, max-age=0");
			response.addDateHeader("Expires", 1L);
		} else {
			//write Cache
			response.addHeader("Cache-Control", "public, max-age=" + getCacheIntervall() * 60); //seconds
			response.addDateHeader("Expires", now + (getCacheIntervall() * 60000));  //milliseconds
		}
	}

	/**
	 * @return the ENCODING
	 */
	protected String getENCODING() {
		return this.ENCODING;
	}

	/**
	 * @param encoding the ENCODING to set
	 */
	protected void setENCODING(String encoding) {
		this.ENCODING = encoding;
	}

	/**
	 * @return the cacheIntervall
	 */
	protected int getCacheIntervall() {
		return this.cacheIntervall;
	}

	/**
	 * @param intervall the cacheIntervall to set
	 */
	protected void setCacheIntervall(int intervall) {
		this.cacheIntervall = intervall;
	}
}